JP6976085B2 - Communication control device and equipment communication system - Google Patents

Description

The present invention relates to a communication control device for bus connection by time division multiplexing access for free channel detection, and an equipment communication system.

Since the communication network of industrial equipment mainly transmits a small amount of information such as the operating status of equipment and control commands, we aimed to reduce costs by using low-speed serial communication compared to the Internet. I came. On the other hand, in recent years, the functions of equipment and devices have become more sophisticated and the transmitted information has been diversified, and the number of equipment and devices compatible with high-speed communication is increasing.

Patent Document 1 describes a method for reducing communication failure (retransmission, etc.) due to interference in each communication method when communication is performed by signals of a plurality of types of communication methods on one transmission path.

Patent Document 2 describes a method for suppressing a communication error when high-frequency transmission data is superimposed on low-frequency transmission data on one transmission path.

Japanese Patent No. 4958640 Japanese Patent No. 5761432

As for the equipment installed in the building, there are cases where equipment with the same performance is introduced all at once at the same time, but old products and new products are often introduced together. For example, the old product only supports low-speed communication, but the new product also supports high-speed communication. Even in an environment where equipment with various communication performances coexist, it is necessary to operate correctly.

If the old product and the new product communicate only with low-speed communication that supports both, the connectivity is guaranteed, but the high-speed communication function of the new product is not used, and the utilization efficiency of the communication network is improved. Go down.

Further, if only the high-speed communication function is continuously used, the utilization efficiency of the communication network is improved, but the control signal of the air-conditioning system that can be transmitted only by low-speed communication is squeezed by the high-speed communication. As a result, the arrival of the control signal (such as the temperature change signal of the air conditioner) to be immediately reflected in the equipment is delayed, which causes inconvenience to the user. In this way, in order to use the equipment network that connects equipment and devices, it is necessary to improve communication efficiency and ensure reliable transmission of important signals.

However, the above-mentioned conventional technology does not correspond to the use in an environment where low-speed communication equipment and high-speed communication equipment coexist, and communication by signals of multiple types of communication methods on the same transmission path (low-speed communication of the old method). In the case of performing high-speed communication using the new method), sufficient consideration has not been given to problems that may occur in communication devices that only support low-speed communication.

For example, in Patent Document 1, a communication device that supports only low-speed communication (first communication method) cannot detect a high-speed communication (second communication method) signal, so that high-speed communication can be performed from another communication device. There is a possibility that a low-speed communication signal will be transmitted without noticing that the signal is being transmitted. In that case, interference occurs on the transmission line and the communication quality deteriorates.

Further, in Patent Document 2, in the case of the random access communication method of avoiding collision by detecting an empty channel, the communication device of the old method cannot detect high-speed communication data (high-frequency transmission data), so that high-speed communication data can be obtained from other communication devices. There is a possibility that low-speed communication data (low-frequency transmission data) will be transmitted without noticing that it has been transmitted. In that case, interference occurs on the transmission line and the communication quality deteriorates.

Therefore, the present invention prevents the data of the first communication method from interfering with the transmission line in which the data of the second communication method is being transmitted in an environment where equipment and devices having various communication performances coexist. The main task is to provide a communication control device that improves the convenience of the entire equipment network and an equipment communication system.

In order to solve the above problems, the communication control device of the present invention has the following configuration.

Channel usage detection period of the first communication method when communicating with a communication unit capable of switching between the first communication method or the second communication method of the time division multiplex access method by the second communication method. The communication unit includes a first communication detection period generation instruction unit for instructing the generation of the channel, and the communication unit uses the channel use based on the channel use detection period generation instruction from the first communication detection period generation instruction unit. A communication control device that transmits a signal including a detection period on a transmission path.

Other means are as described in the claims.

According to the present invention, in an environment where equipment and devices having various communication performances coexist, it is possible to prevent the data of the first communication method from interfering with the transmission line during transmission of the data of the second communication method. It is possible to provide a communication control device that improves the convenience of the entire equipment network and an equipment communication system.

It is a block diagram of the equipment communication system in Example 1. FIG. It is a device management table of the equipment communication system in Example 1. It is a detailed block diagram of each equipment apparatus of the equipment communication system in Example 1. FIG. It is a figure which shows an example of the communication data format in Example 1. FIG. It is explanatory drawing of the communication mode of the equipment network in Example 1. FIG. It is explanatory drawing of the communication mode of the equipment network in Example 1. FIG. It is a sequence diagram of the unicast communication in Example 1. FIG. It is a sequence diagram of the multicast communication in Example 1. FIG. It is explanatory drawing of the high-speed communication detection operation of the low-speed apparatus in Example 1. FIG. It is explanatory drawing of the high-speed communication detection operation of the low-speed apparatus in Example 1. FIG. It is explanatory drawing of the high-speed communication detection operation of the low-speed apparatus in Example 1. FIG. It is explanatory drawing of the high-speed communication detection operation of the low-speed apparatus in Example 1. FIG. It is a figure which shows an example of the signal waveform in Example 1. FIG. It is a detailed block diagram of each equipment apparatus of the equipment communication system in Example 2. FIG. It is a figure which shows an example of the signal waveform in Example 2. FIG. It is a figure which shows an example of the signal waveform in Example 2. FIG. It is a figure which shows an example of the signal waveform in Example 2. FIG. It is a detailed block diagram of the high-speed apparatus of the equipment communication system in Example 3. FIG. It is a detailed block diagram of the low-speed apparatus of the equipment communication system in Example 3. FIG. It is a figure which shows an example of the frequency spectrum of the signal in Example 3. FIG. It is a flowchart which shows the transmission / reception processing of the low-speed apparatus in Examples 1 to 3. It is a flowchart which shows the detail of the packet creation process in Examples 1 to 3. It is a flowchart which shows the detail of the packet transmission processing in Examples 1 to 3. It is a flowchart which shows the reception process of the high-speed apparatus in Examples 1 to 3. It is a flowchart which shows the transmission process (first time) of the high-speed apparatus in Examples 1 to 3. It is a flowchart which shows the transmission process (the second and subsequent times) of the high-speed apparatus in Examples 1 to 3. It is explanatory drawing of the data division method in Examples 1 to 3.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(System configuration)
First, the equipment communication system of the first embodiment will be described with reference to FIGS. 1 to 10.

FIG. 1 is a configuration diagram of the equipment communication system of this embodiment. The equipment communication system is composed of a higher-level device 9 that manages the equipment of the entire building and each equipment device connected to the equipment network 5. Here, the equipment is the indoor units 21 to 26 of the air conditioner, the outdoor units 31, 32, the accompanying devices 41 and 42 such as lighting equipment and security equipment, and the management device for managing each of these devices. It is a general term for 11 and 12.

Each equipment is configured as a computer having a CPU (Central Processing Unit), a memory, a storage means (storage unit) such as a hard disk, and a network interface. This computer operates a control unit (control means) composed of each processing unit by executing a program (also referred to as an application or other application) read into the memory by the CPU.

The host device 9 is connected to the management device 11 by a network different from the equipment network 5. The host device 9 controls each facility device from the management device 11 via the facility network 5 by transmitting a device control command to the management device 11 in order to optimize the power consumption of the entire building, for example.

Each equipment device connected to the equipment network 5 can transmit and receive in both directions (arbitrary direction). For example, the management device 11 transmits the temperature adjustment signal of the air conditioner to the indoor unit 21, and the indoor unit 21 notifies the management device 11 of the indoor temperature information.

The equipment network 5 is a network capable of switching a plurality of communication modes in time series for communication. The equipment network 5 switches between low-speed communication as the first communication mode and high-speed communication as the second communication mode, for example. Then, during the low-speed communication time zone, important control signals such as the temperature adjustment signal of the air conditioner are transmitted, and during the high-speed communication time zone, a large amount of data such as the latest version of the air conditioner firmware is transmitted. If the data content according to the mode is transmitted, the equipment network 5 can be effectively utilized.

Here, the communication mode is switched based on the normal communication mode, and when the communication mode change trigger occurs, the communication mode is switched to another mode. In the following, low-speed communication will be described as a normal communication mode, and high-speed communication will be described as a communication mode caused by a trigger. On the other hand, high-speed communication may be set as a normal communication mode, and low-speed communication may be set as a communication mode caused by a trigger.

Further, each equipment device of the equipment communication system is classified into either a low-speed device corresponding only to low-speed communication and a high-speed device corresponding to both low-speed communication and high-speed communication.

In FIG. 1, the thick-wire device shows a high-speed device that supports both high-speed communication and low-speed communication (indoor unit 21 and the like), and the thin-wire device shows a low-speed device that supports only low-speed communication (indoor unit 23 and the like). Then, in the equipment communication system of this embodiment, each equipment is grouped into two groups. The first group 8a is a group of only high-speed devices, which is composed of a management device 11, an indoor unit 21 and 22, an outdoor unit 31, and a device 41, which are indicated by thick lines. On the other hand, the second group 8b is a low-speed device and a high-speed device including the management device 12, the indoor unit 23, 25, 26, the outdoor unit 32, the device 42 shown by the thin line, and the indoor unit 24 shown by the thick line. It is a group in which devices are mixed.

Each group is an aggregate of equipment belonging to the same refrigerant system, and the indoor units 21 and 22 and the outdoor unit 31 are connected by a first refrigerant pipe (shown by a broken line) for supplying the refrigerant gas, and the indoor unit 23 is connected. -26, the outdoor unit 32 is connected by a second refrigerant pipe (shown by a broken line) for supplying the refrigerant gas.

FIG. 2 is an example of the device management table 101 of the equipment communication system. As illustrated here, in the device management table 101, the device type, the address of each device, and whether or not high-speed communication is supported (high-speed device corresponding to ○, low-speed device not supported by ×) are shown in the device management table 101. The group to which the device belongs is listed. The device management table 101 is individually stored in each equipment device, but the contents of the device management table stored in each facility device may be all entries in the table, or may be a device that is not a communication partner from the viewpoint of itself. You may exclude the entry of. The device that does not become a communication partner is a device of the same device type as itself, for example, an indoor unit 22 when itself is an indoor unit 21.
(Communication device configuration)
FIG. 3 is a detailed configuration diagram of data transmission / reception related parts in each equipment of the equipment communication system, and includes a storage unit 51, a load unit 52, a communication unit 53, and a control unit 54 (eg, a microcomputer). However, a mechanism as a low-speed device and a mechanism as a high-speed device are built in one housing. Various parameters (fan rotation speed, etc.) related to the load unit 52 are stored in the storage unit 51. The load unit 52 is, for example, a display display in the case of the device type "management device", a fan in the case of the device type "indoor unit", a compressor in the case of the device type "outdoor unit", and lighting in the case of the device type "device". Lamps, image sensor, etc. In the following, the communication unit 53 and the control unit 54 may be collectively referred to as a communication control device.

When operating this equipment as a "low-speed device", the coding unit 61, the modulation / demodulation unit 62, the decoding unit 63, and the free channel detection unit 64 in the communication unit 53 are used, and the transmission data is generated in the control unit 54. The unit 71, the transmission unit 72, the reception unit 73, the reception data analysis unit 74, and the communication control unit 75 may be used.

On the other hand, when operating this equipment as a "high-speed device", in addition to the configuration of the low-speed device described above, the communication speed determination unit 76, the communication speed switching unit 77, and the low-speed detection period generation instruction unit 78 in the control unit 54 are added. You just have to prepare.

First, a case where the equipment is operated as a low-speed device will be described. As the low-speed device, the communication function shown below is used.

The coding unit 61 returns to zero (hereinafter referred to as NRZ) from a coding process (example: Non Return to Zero (hereinafter referred to as NRZ)) code for the transmission data 501 notified from the transmission unit 72 (eg, UART transmission circuit). , Converted to a code) (referred to as RZ).

The modulation / demodulation unit 62 includes a modulation circuit and a demodulation circuit, and a transmission coded signal 502 encoded by the coding unit 61 is modulated and transmitted to the equipment network 5. Further, the signal received from the equipment network 5 is demodulated and notified to the decoding unit 63. It should be noted that a configuration in which a low-pass filter is provided in front of the demodulation circuit is common. Further, a process of transmitting and receiving signals by a baseband method that does not use high frequencies will be described as being included in the modulation / demodulation unit 62 in a broad sense.

The decoding unit 63 performs decoding processing (eg, conversion from the RZ code to the NRZ code) on the received coded signal 503 demodulated by the modulation / demodulation unit 62, and notifies the receiving unit 73 of the received data 504.

The free channel detection unit 64 monitors the signal demodulated by the modulation / demodulation unit 62, and notifies the transmission unit 72 and the reception unit 73 of the availability status of the equipment network 5 which is a transmission line. The equipment network 5 is a bus type, and has time-division multiple access for free channel detection with other equipment communication systems.

The receiving unit 73 (eg, UART receiving circuit) receives the signal from the decoding unit 63 and notifies the received data 504 to the received data analysis unit 74.

The received data analysis unit 74 analyzes the content of the packet included in the received data 504 and notifies the communication control unit 75.

The communication control unit 75 executes data access processing to the storage unit 51 and control processing to the load unit 52 based on the contents of the analyzed packet. Further, based on the instruction of the communication control unit 75, the transmission data generation unit 71 generates a packet to be notified to another device and notifies the transmission unit 72. The transmission unit 72 notifies the coding unit 61 of the transmission data 501. The communication control unit 75 may voluntarily issue an instruction to generate transmission data based on the state of the load unit 52.

Next, a case where the equipment is operated as a high-speed device will be described. The high-speed device can switch between high-speed communication and low-speed communication so as to communicate with the low-speed device using low-speed communication and communicate with the high-speed device using high-speed communication.

The communication speed determination unit 76 determines whether or not to switch between low-speed communication and high-speed communication based on the speed switching trigger signal received by the received data analysis unit 74. The determination result is notified to the communication control unit 75 and the communication speed switching unit 77.

When the communication speed switching unit 77 instructs the transmitting unit 72, the receiving unit 73, and the communication unit 53 to switch from low-speed communication to high-speed communication to transmit and receive signals, the transmitting unit 72, the receiving unit 73, and the communication unit 53 perform high-speed communication. Performs communication processing. On the other hand, when the communication speed switching unit 77 instructs the transmitting unit 72, the receiving unit 73, and the communication unit 53 to switch from high-speed communication to low-speed communication to transmit and receive signals, the transmitting unit 72, the receiving unit 73, and the communication unit 53 are instructed. Performs processing for low-speed communication. Instead of receiving the trigger signal from the outside, the communication control unit 75 may generate a trigger for switching from low-speed communication to high-speed communication when the device itself requires high-speed communication.

The low-speed detection period generation instruction unit 78 instructs the timing of inserting the channel use detection signal (low-speed detection period) for the low-speed device as described later.
(Basic communication method)
FIG. 4 is an explanatory diagram of packets exchanged in the equipment communication system. The packet format 80 includes a header column 81, a data column 82, and a parity column 83 in this order from the beginning. The parentheses in each column in the packet format 80 indicate the amount of data (unit B: bytes) in each column. For example, the header column 81 has a fixed length of 8 bytes, and the data column 82 has a variable length.

The header column 81 is further composed of a device type column 84, a source address column 85, a destination address column 86, a communication type column 87, and a data length column 88. The data length column 88 indicates the data length of the data column 82.

The address of the source device of the packet is described in the source address field 85, and the address of the destination device of the packet is described in the destination address field 86. Alternatively, when specifying multiple packet destination devices at once, specify the multicast address "0xFFFF" that specifies all devices as the destination device address, or the device group grouped using specific bits. The multicast address is listed.

For the packet format 80, the same data format may be used for low-speed communication and high-speed communication. In the case of high-speed communication, the high-speed device may transmit the header column 81 using the low-speed communication, and then switch the subsequent data column 82 and the parity column 83 to high-speed communication for transmission. Alternatively, the high-speed device may transmit the header column 81, the data column 82, and the parity column 83 all together by high-speed communication.

Further, in this embodiment, the term "multicast" is used to collectively mean transmission to a plurality of destination devices. In order to realize this broad-sense multicast, for example, narrow-sense multicast or broadcast defined by IP (Internet Protocol) may be used.

Table 111 shown in Table 1 shows a description example of the device type column 84 indicating the device type of the source device. For example, when the source device is the indoor unit 21, "0x02" indicating the indoor unit is described in the device type column 84. Further, the device type "equipment" may be further subdivided based on the type of the device and assigned different values.

Table 112 shown in Table 2 shows a description example of the communication type column 87 indicating the purpose of the packet. For each value from No. 1 (control) to No. 6 (high-speed communication), either ON or OFF can be specified. Therefore, in the communication type column 87, the logical sum of each value shown in FIG. 4 is described. For example, when it is desired to specify "response required" and "batch control" at the same time, the logical sum "0x84" of "0x80" and "0x04" is described in the communication type column 87. Further, "0x0F" is an undefined value in the low-speed device, and indicates that the communication following the header column 81 is high-speed in the high-speed device.

Table 113 shown in Table 3 shows a description example of the data length column 88. When the value in the data length column 88 is 0x0000 to 0x0030, that value becomes the data length as it is. On the other hand, when the value of the data length column 88 is from 0x0040 to, as shown in FIG. 4, information about the high-speed communication (high-speed communication number of times, high-speed communication period) can be specified only in the case of the high-speed device.

5A and 5B are explanatory views of a signal to be modulated on the equipment network 5 and a communication mode of the equipment. The time-series graphs 121 and 122 show, in order from the top, a packet transmitted by low-speed communication, a packet transmitted by high-speed communication, and a communication mode (state) of the equipment network 5. In the communication mode of the equipment network 5, the period described as "high speed" is the period of high speed communication, and the others are the period of low speed communication.

The time-series graph 121 shown in FIG. 5A shows an example in which one high-speed communication is performed according to a one-time trigger transmitted by low-speed communication. In this example, after the data packet of low-speed communication is transmitted, one trigger that enables one high-speed communication is transmitted by low-speed communication. This one-time trigger is a header column 81 in which 0x0F is set in the communication type column 87, and is also referred to as a high-speed trigger below.

Since the high-speed device that has received this high-speed trigger is ready to receive the packet in high-speed communication, the subsequent packet is transmitted in high-speed communication. Then, since transmission / reception does not occur for a predetermined period after one high-speed communication, the communication mode of the equipment network 5 returns to normal low-speed communication. Even if the low-speed device receives the high-speed trigger, the value "0x0F" in the communication type column 87 is undefined for the low-speed device, so the high-speed trigger is appropriately ignored and the low-speed device gives an abnormal response. There is nothing to do.

On the other hand, the time-series graph 122 shown in FIG. 5B shows an example in which high-speed communication is performed a plurality of times according to a period trigger transmitted by low-speed communication. In this example, after the period T1 which is the waiting time provided after the data packet transmission of the low-speed communication, the period trigger which enables the high-speed communication continuously for a predetermined period is transmitted by the low-speed communication. This period trigger is a header column 81 in which 0x0F is set in the communication type column 87 and the high-speed communication period (or the number of high-speed communications) is specified in the data length column 88.

All high-speed devices that receive the trigger during this period are ready to send and receive packets for high-speed communication. Then, any high-speed device may perform high-speed communication within the high-speed communication period. Each packet transmitted by high-speed communication has a margin of period T2 so as not to collide with each other. Then, after the high-speed communication period ends, the low-speed communication returns after the unused period T3 in which the packet does not flow in the equipment network 5. By setting period T1 ≦ period T3 and period T2 <period T3, it is possible to prevent the low-speed device from transmitting data during the high-speed communication period.

FIG. 6 is a sequence diagram of 1: 1 communication between each equipment. In each sequence diagram including FIG. 6, the high-speed device and high-speed communication are described by thick lines, and the high-speed device and low-speed communication are described by thin lines, following FIG. It should be noted that the main operating unit in each sequence diagram is merely an example for explaining the operation of the high-speed device and the operation of the low-speed device in an easy-to-understand manner, and even if a device other than this example is operated as a high-speed device or a low-speed device. good.

In the sequence of S11, the management device 12 individually transmits the “response required” packet described in Table 112 to each equipment device (indoor unit 23, indoor unit 21, management device 11) by low-speed communication (“send”). "Illustrated). Then, each equipment device that has received the "response required" packet individually responds to the management device 12 by low-speed communication (shown as "ack"). As a result, the management device 12 can grasp that communication with each equipment device is possible.

S12 is an example of high-speed communication of only packet transmission between the management device 11 and the indoor unit 21, both of which are high-speed devices. First, the indoor unit 21 transmits one high-speed trigger shown in the time-series graph 121 to the management device 11 by low-speed communication (the broken line arrow indicates the trigger). As a result, the following packets are transmitted from the indoor unit 21 to the management device 11 at high speed. On the other hand, since the packet response from the management device 11 to the indoor unit 21 is not transmitted following the high-speed trigger, it is transmitted in the low-speed communication mode.

S13 is an example of high-speed communication of a combination of packet transmission and its response. Similar to S12, the management device 11 transmits the high-speed trigger to the indoor unit 21 to transmit the subsequent “response required” packet to the indoor unit 21 in the high-speed communication mode. Further, the indoor unit 21 transmits a high-speed trigger to the management device 11, so that the subsequent response packet is transmitted to the management device 11 in the high-speed communication mode.

S14 is an example in which a high-speed communication period is specified and a combination of a “response required” packet transmission and the response packet is continuously transmitted at high speed. In this example, the management device 11 transmits the high-speed trigger shown in the time-series graph 122 to the indoor unit 21 in the low-speed communication mode, and the subsequent high-speed communication period is a packet between the indoor unit 21 and the management device 11. Both transmission and reception are performed in the high-speed communication mode.

On the other hand, after the high-speed communication period set by the period trigger has elapsed, in order to return from the high-speed communication mode to the low-speed communication mode, the packet transmission from the indoor unit 21 to the management device 11 in S15 and the indoor unit from the management device 11 The packet response to the machine 21 is performed by low-speed communication.

As described above, in FIG. 6, by utilizing the high-speed trigger, both low-speed communication between low-speed devices and low-speed communication between low-speed devices and high-speed devices can be performed at high speed as communication on the same equipment network 5. Both low-speed communication between devices and high-speed communication between high-speed devices are possible. Further, in S14, by using a high-speed trigger for which a high-speed communication period is specified, high-speed communication can be performed more efficiently than a method of transmitting a high-speed trigger each time.

FIG. 7 is a sequence diagram of multicast communication between each equipment.

In the sequence of S21, the management device 12 transmits a “response required” packet by low-speed communication to each equipment device (indoor unit 23, management device 11, indoor unit 21, indoor unit 22) by multicast (FIG. FIG. Then, "M" indicating multicast is followed by "send" indicating a transmitted packet). Then, each equipment device that has received the "response required" packet individually responds to the management device 12 by low-speed communication (shown as "ack"). Here, since four packet responses arrive at one management device 12, each equipment device waits for a transmission waiting time (offset time) different from that of another device so that the arrival times do not collide. You should respond from. This offset time is calculated from, for example, the device address of each equipment.

Further, in S22, the management device 11 notifies each high-speed device (indoor unit 21, indoor unit 22) of a high-speed trigger for which a high-speed communication period is specified by multicast (shown as “M-period trigger”). Then, the management device 11 transmits the packet of "response required" to each high-speed device by multicast at high speed. Each high-speed device that receives this packet individually transmits the response packet in the high-speed communication mode within the high-speed communication period.

In S23, after the high-speed communication period specified in S22 ends, the management device 11 performs multicast transmission without a response to each equipment device (four left and right).

As described above, in FIG. 7, by using the multicast communication together with the high-speed trigger, it is possible to perform simultaneous communication in low-speed communication and simultaneous communication in high-speed communication as communication on the same equipment network 5.
(Basics of interference occurrence cases and countermeasures)
Next, a comparative explanation of the time-series graph 131 of FIG. 8A in which communication between the high-speed device and the low-speed device cannot be normally performed after the transmission of the trigger once and the time-series graph 132 of FIG. Further, a comparison explanation will be made between the time-series graph 133 of FIG. 9A in which communication between the high-speed device and the low-speed device cannot be normally performed after the transmission of the period trigger and the time-series graph 134 of FIG. 9B in which it is avoided by the present embodiment. The graphs of the time series graphs 131, 132, 133, and 134 are, in order from the top, low-speed communication data transmitted by the low-speed device, low-speed communication data transmitted by the high-speed device, and high-speed communication transmitted by the high-speed device. Show the data.

The time series graph 131 of FIG. 8A shows an example in which one high-speed communication is performed after one trigger of low-speed communication. At this time, the low-speed device can detect the carrier for the one-time trigger of the low-speed communication, but cannot detect the carrier for the high-speed data of the subsequent high-speed communication (indicated by "x" in FIG. 8A). Low-speed data may be transmitted after the elapse of the period T1 which is the waiting time of. If high-speed data transmission from the high-speed device and low-speed data transmission from the low-speed device are performed at the same time, a communication collision will occur on the transmission path. The free channel detection process of the low-speed device is performed by the free channel detection unit 64. For example, this problem occurs when the free channel detection unit 64 includes a low-pass filter and cannot detect high-speed communication.

On the other hand, the time-series graph 132 of FIG. 8B describes a method of avoiding the defect of FIG. 8A, and by transmitting a low-speed detection period (channel use detection signal) that can be detected by the low-speed device in a timely manner, the high-speed signal can be obtained. The carrier can be detected by the low-speed device even during the transmission period. Specifically, when the high-speed device transmits high-speed communication data, a channel use detection signal (low-speed detection period) for the low-speed device is inserted at the beginning of the data and every time the period T4 (<T1) elapses. At this time, the transmission data for high-speed communication is divided into packet units, and in the example of FIG. 8B, one high-speed data is divided into four. Due to the low speed detection period inserted in this way, the low speed device can detect that the transmission line is in use at predetermined intervals. Then, after the high-speed device completes the transmission of the last low-speed detection period, the free channel detection process of the period T1 is performed, and after confirming that the transmission line is not used, the low-speed communication data is transmitted, so that the low-speed communication data is transmitted on the transmission line. Communication conflicts can be avoided and communication can be performed normally. The low-speed detection period generation instruction unit 78 shown in FIG. 3 indicates the insertion timing of the low-speed detection period.

The time series graph 133 of FIG. 9A shows an example in which high-speed communication is performed a plurality of times after the period trigger of low-speed communication. Similar to FIG. 8A, while the high-speed device is transmitting high-speed communication data, the low-speed device may not be able to detect that communication is being performed on the transmission path even if the free channel detection process is performed, and the period After the free channel detection process of T1, low-speed communication data is transmitted, and a communication collision occurs on the transmission path.

On the other hand, the time-series graph 134 of FIG. 9B explains a method of avoiding the defect of FIG. 9A, and is during the transmission period of the high-speed signal by inserting the low-speed detection period in which the carrier can be detected by the low-speed device in a timely manner. However, the low-speed device can detect the carrier. Specifically, when the high-speed device transmits high-speed communication data, a channel use detection signal (low-speed detection period) for the low-speed device is inserted at the beginning of each high-speed communication data. Due to the low speed detection period inserted in this way, the low speed device can detect that the transmission line is in use at predetermined intervals. Then, after the high-speed device completes the transmission of the last low-speed detection period, the free channel detection process of the period T1 is performed, and after confirming that the transmission line is not used, the low-speed communication data is transmitted, so that the low-speed communication data is transmitted on the transmission line. Communication conflicts can be avoided and communication can be performed normally. Also in FIG. 9B, similarly to FIG. 8A, the low speed detection period generation instruction unit 78 instructs the insertion timing of this low speed detection period.

In the time series graph 133 of FIG. 9A, if the low-speed device receives the period trigger in the low-speed communication and can recognize that the high-speed communication is performed for a predetermined time, the communication collision does not occur on the transmission path. Can be done. However, in the equipment communication system having a long product life, the already installed low-speed device cannot recognize the new specification "period trigger in low-speed communication". Even in such a case, the method of this embodiment is effective. Further, although the low-speed detection period is shown as high-speed communication data in FIGS. 8B and 9B, this signal may be treated as low-speed communication data.

Next, with reference to FIG. 10, a specific example of the low-speed detection period and the relationship between whether or not the carrier of high-speed communication data can be detected by the free channel detection unit 64 of the low-speed device depending on the presence or absence of the low-speed detection period will be described.

In FIG. 10, the signal waveforms 141 and 143 are transmission signals on the equipment network 5, the signal waveform 141 does not include the low-speed detection period, and the signal waveform 143 shows the signal waveform 143. Further, the signal waveforms 142 and 144 are received signals inside the empty channel detection unit 64 of the low-speed device, the signal waveform 142 is a signal waveform 141 processed by a low-pass filter, and the signal waveform 144 is a signal waveform 143. It shows the one that has been filtered through the low frequency range.

Here, as an example of the communication method, a case where the modulation / demodulation unit 62 uses the baseband method and the transmission unit 72 uses the pace synchronization will be described. In this case, the free channel detection unit 64 of the low-speed device detects the carrier on the equipment network 5 by detecting the start bit of the pace synchronization communication. In the following, the HIGH level will be described as a no-signal state, and the LOW level will be described as a Start bit.

The signal waveform 141 shows a signal waveform of high-speed communication data transmitted by the high-speed device on the equipment network 5. Since it is a baseband type pacing synchronous communication, it is basically a square wave in which a HIGH signal and a LOW signal are mixed.

The signal waveform 142 shows a signal waveform in which the signal waveform 141 is received inside the free channel detection unit 64 of the low-speed device. The free channel detection unit 64 generally includes a low-pass filter, and this low-pass filter is designed to have a large time constant in order to receive a signal for low-speed communication. Since the waveform of the signal is distorted and the LOW period is short, it may not be possible to drop to the LOW level. That is, while the high-speed device is transmitting high-speed communication data, the low-speed device cannot detect the LOW level Start bit even if the free channel detection process is performed, and cannot detect that communication is being performed on the transmission path. There is.

Therefore, in this embodiment, as shown in the signal waveform 143, the signal waveform when the high-speed device inserts the low-speed detection period between the high-speed communication packets is shown based on the instruction of the low-speed detection period generation instruction unit 78. .. Here, as the low-speed detection period, the Start bit for low-speed communication, that is, the clock for high-speed communication is used to transmit a continuous LOW signal a plurality of times. This is performed by the communication unit 53 that has received the instruction from the low-speed detection period generation instruction unit 78.

The signal waveform 144 shows a signal waveform in which the signal waveform 143 is received inside the free channel detection unit 64 of the low-speed device. By receiving a LOW signal that is sufficiently longer than the time constant of the low-pass filter included in the signal waveform 143, unlike the signal waveform 142, the signal waveform 144 can receive a signal that has dropped to the LOW level. Become.

As a result, the free channel detection unit 64 of the low-speed device can detect the Start bit in the form of either an edge trigger or a level trigger, and can correctly detect the use of the transmission line. Therefore, even if a low-speed device that supports only the old method of low-speed communication and a high-speed device that supports the new method of high-speed communication exist on the same transmission path, the low-speed device is being transmitted from the high-speed device during high-speed communication data transmission. Can avoid the situation of transmitting low-speed communication data, and can perform communication on the transmission path without interference.

When the low-speed device receives the signal waveform 143, the signal flows to the modulation / demodulation unit 62, the decoding unit 63, the reception unit 73, and the received data analysis unit 74, but in the case of the low-speed device, synchronization is not achieved. It is interpreted as abnormal data by parity check and CRC and discarded, so there is no particular problem. Even in the case of a high-speed device, if such data is specified as an abnormal value, it is interpreted as abnormal data by the parity check or CRC and discarded.

Alternatively, during the low-speed detection period, the communication unit 53 is temporarily switched to the low-speed communication mode, and one LOW signal is transmitted by the low-speed communication clock to start the low-speed communication start bit. Can be considered. This is performed by the communication unit 53 that has received the instruction from the low-speed detection period generation instruction unit 78. As a result, even if a communication device that supports only the old method of low-speed communication and a communication device that supports the new method of high-speed communication exist on the same transmission line, communication can be performed without interference on the transmission line. can.

Further, as yet another method, a method of transmitting one character data for high-speed communication in which all bits are 0 (LOW) during the low-speed detection period can be considered. This is performed by the transmission data generation unit 71 that receives the instruction from the low-speed detection period generation instruction unit 78. As a result, even if a communication device that supports only the old method of low-speed communication and a communication device that supports the new method of high-speed communication exist on the same transmission line, communication can be performed without interference on the transmission line. can. Moreover, the condition is that the signal transmitted by the communication unit 53 is an NRZ signal, but since it can be handled only by changing the software of the control unit 54, it is easier than the above example in which the communication unit 53 inserts a signal for low-speed detection. Can be realized.

Next, the equipment communication system of the second embodiment will be described with reference to FIGS. 11 to 14. In the equipment communication system of the first embodiment, an example of using pacing synchronization as a communication method has been described, but in this embodiment, an example of using an AMI code as a communication method will be described. It should be noted that the common points with the first embodiment are omitted.

As the equipment communication system of the second embodiment, when the modulation / demodulation unit 62 is a baseband method, a pace synchronization, and a communication method using an AMI (Alternate Mark Inversion) code, high-speed communication is performed by free channel detection processing of a low-speed device. A method of inserting a low-speed detection period based on an instruction of the low-speed detection period generation instruction unit 78 will be described when data cannot be detected and in order to solve the problem. In this embodiment, the influence of the code conversion circuit will be focused on, not the influence of the low-pass filter. For the sake of simplicity, in this description, 1 bit of the high-speed signal is assumed to be sufficiently larger than the time constant of the low-pass filter of the receiving circuit of the low-speed device, and the influence of the waveform distortion described in the first embodiment is excluded.

FIG. 11 is a detailed configuration diagram of each equipment device of the equipment communication system according to the present embodiment. The same functions as those of the equipment shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 11, the coding unit 61 and the decoding unit 63 shown in FIG. 3 are specified by the NRZ / RZ conversion unit 201 and the RZ / NRZ conversion unit 202, respectively. Further, instead of the free channel detection unit 64 included in the communication unit 53, the control unit 54 includes a free channel detection unit 203.

The NRZ / RZ conversion unit 201 converts the NRZ system signal received from the transmission unit 72 into the RZ system and notifies the modulation / demodulation unit 62. The RZ method has an advantage that it is easy to take timing because it returns to 0 potential for each bit.

The RZ / NRZ conversion unit 202 converts the RZ system signal received from the modulation / demodulation unit 62 into the NRZ system, and notifies the reception unit 73 and the free channel detection unit 203.

The free channel detection unit 203 monitors the signal (received data signal 504) received from the RZ / NRZ conversion unit 202, and determines the free status of the transmission line. Specifically, the Start bit detection of the pace synchronization communication is performed.

Next, with reference to FIG. 12, the signal waveform at each measurement point from the transmission of the low-speed communication signal to the reception by the low-speed device will be described.

The signal waveform 151 shows the waveform of the transmission data 501 of the NRZ method output by the transmission unit 72 of the low-speed device.

The signal waveform 152 shows the waveform of the transmission coded signal 502 of the RZ method output by the NRZ / RZ conversion unit 201 of the low-speed device. The NRZ / RZ conversion unit 201 converts a 1-bit LOW signal into a 2-bit LOW-HIGH signal with a half time width, and interprets the 1-bit HIGH signal as a 2-bit HIGH-HIGH signal with a half time width. Generate a system signal.

The signal waveform 153 shows an AMI-code-modulated modulated signal waveform transmitted on the equipment network 5 by the modulation / demodulation unit 62 of the low-speed device.

The signal waveform 154 shows the waveform of the received coded signal 503 obtained by demodulating the signal waveform 153 by the modulation / demodulation unit 62 of another low-speed device that has received the signal waveform 153 from the equipment network 5. This has the same shape as the signal waveform 152.

The signal waveform 155 shows an NRZ system signal waveform output by the RZ / NRZ conversion unit 202 of another low-speed device that has received the signal waveform 153 from the equipment network 5. The RZ / NRZ conversion unit 202 converts the LOW signal of the RZ system signal into an NRZ system signal by extending the LOW signal of the RZ system signal by a fixed time length by a so-called waveform expansion circuit. This has the same shape as the signal waveform 151. This signal is the received data 504 of FIG. 11 and is notified to the receiving unit 73. Further, using the same received data 504, the free channel detection unit 203 determines whether or not the transmission line is in use. The free channel detection unit 203 recognizes the start bit of the pace synchronization communication by detecting the falling from HIGH to LOW, and determines that the transmission line is in use. Then, in the signal waveform 155, since the falling edge from HIGH to LOW can be detected, the use of the transmission line can be detected.

On the other hand, FIG. 13 is an explanatory diagram of the signal waveform at each measurement point until the conventional low-speed device receives the high-speed communication signal transmitted by the high-speed device, and the low-speed device cannot detect the use of the transmission line. It explains the situation.

The signal waveform 161 shows the waveform of the transmission data 501 of the NRZ method output by the transmission unit 72 of the high-speed device.

The signal waveform 162 shows the waveform of the transmission coded signal 502 of the RZ method output by the NRZ / RZ conversion unit 201 of the high-speed device. The NRZ / RZ conversion unit 201 converts a 1-bit LOW signal into a 2-bit LOW-HIGH signal with a half time width, and interprets the 1-bit HIGH signal as a 2-bit HIGH-HIGH signal with a half time width. Generate a system signal.

The signal waveform 163 shows an AMI code-modulated signal waveform transmitted by the modulation / demodulation unit 62 of the high-speed device on the equipment network 5.

The signal waveform 164 shows the waveform of the received coded signal 503 in which the modulation / demodulation unit 62 of the low-speed device that received the signal waveform 163 from the equipment network 5 AMI-coded the signal waveform 163. This has the same shape as the signal waveform 162.

The signal waveform 165 shows an NRZ type signal waveform output by the RZ / NRZ conversion unit 202 of the low-speed device that has received the signal waveform 163 from the equipment network 5. As described in FIG. 12, the RZ / NRZ conversion unit 202 extends the LOW signal of the signal waveform 164 input by the waveform expansion circuit by a fixed time length, so that the RZ type signal waveform 164 in which the LOW signal frequently appears is used. The converted NRZ system signal waveform 165 is stuck to LOW, and the original signal waveform 161 is not restored. This signal waveform 165 is notified to the receiving unit 73 and the free channel detecting unit 203 as received data 504.

Since the received data 504 is originally a high-speed communication signal transmitted by the high-speed device, in the low-speed device that is not synchronized, the receiving unit 73 or the receiving data analysis unit 74 in the subsequent stage performs a parity check or CRC. It is interpreted as abnormal data and discarded, so there is no particular problem. On the other hand, the free channel detection unit 203 cannot detect the falling from HIGH to LOW and cannot recognize the Start bit of the pace synchronization communication, so that it is determined that the transmission line is in a free state. That is, while the high-speed device is transmitting high-speed communication data, the low-speed device may not be able to detect the Start bit even if the free channel detection process is performed, and may not be able to detect that communication is being performed on the transmission path. Then, when the low-speed device misunderstood that the transmission line is free starts data transmission, the carrier collision on the transmission line shown in FIGS. 8A and 9A occurs.

FIG. 14 illustrates the method of the present embodiment for solving the problem described with reference to FIG. 13, and the high-speed device has a low-speed detection period between packets of high-speed communication based on the instruction of the low-speed detection period generation instruction unit 78. It is explanatory drawing of the signal waveform at each measurement point until the low speed apparatus receives.

The signal waveform 171 shows the waveform of the transmission data 501 of the NRZ method output by the transmission unit 72 of the high-speed device. Here, the high-speed device inserts a low-speed detection period signal between packets of high-speed communication based on the instruction of the low-speed detection period generation instruction unit 78. In this example, as the low-speed detection period, one character data for high-speed communication in which all bits are 1 (HIGH) is transmitted. This is performed by the transmission data generation unit 71 that receives the instruction from the low-speed detection period generation instruction unit 78.

The signal waveform 172 shows the waveform of the transmission coded signal 502 of the RZ method output by the NRZ / RZ conversion unit 201 of the high-speed device. The NRZ / RZ conversion unit 201 converts a 1-bit LOW signal into a 2-bit LOW-HIGH signal with a half time width, and interprets the 1-bit HIGH signal as a 2-bit HIGH-HIGH signal with a half time width. Generate a system signal.

The signal waveform 173 shows an AMI code-modulated signal waveform transmitted by the modulation / demodulation unit 62 of the high-speed device on the equipment network 5.

The signal waveform 174 shows the waveform of the received coded signal 503 in which the modulation / demodulation unit 62 of the low-speed device that received the signal waveform 173 from the equipment network 5 AMI-coded the signal waveform 173. This has the same shape as the signal waveform 172.

The signal waveform 175 shows an NRZ system signal waveform output by the RZ / NRZ conversion unit 202 of the low-speed device that has received the signal waveform 173 from the equipment network 5. As described in FIGS. 12 and 13, the RZ / NRZ conversion unit 202 extends the LOW signal of the signal waveform 174 input by the waveform expansion circuit by a fixed time length, but the waveform is generated in the signal waveform 171 transmitted by the high-speed device. Since the low-speed detection period (HIGH signal period) sufficiently longer than the extension time of the extension circuit is provided, the signal waveform 175 restored by the low-speed device can return to HIGH unlike the signal waveform 165 of FIG. This signal waveform 175 is notified to the receiving unit 73 and the free channel detecting unit 203 as received data 504.

Since the received data 504 is originally a high-speed communication signal transmitted by the high-speed device, in the low-speed device that is not synchronized, the receiving unit 73 or the receiving data analysis unit 74 in the subsequent stage performs a parity check or CRC. It is interpreted as abnormal data and discarded, so there is no particular problem. Further, in the free channel detection unit 203, since the next character causes a fall from HIGH to LOW, the Start bit of the pace synchronization communication can be recognized, and it is determined that the transmission line is in use.

As a result, the start bit can be detected by the free channel detection unit 203 of the low-speed device, and the use of the transmission line can be correctly detected. Therefore, even if a low-speed communication device that supports only the old method of low-speed communication and a high-speed communication device that supports the new method of high-speed communication exist on the same transmission path, high-speed communication data is being transmitted from the high-speed communication device. It is possible to avoid the situation where the low-speed communication device transmits low-speed communication data, and it is possible to perform communication on the transmission path without interference.

When the high-speed device receives the signal waveform 173, the signal flows to the modulation / demodulation unit 62, the RZ / NRZ conversion unit 202, the reception unit 73, and the reception data analysis unit 74, but the continuous HIGH data is defined as an abnormal value. If it is set, it will be interpreted as abnormal data by parity check and CRC and discarded.

Further, as another method, a method in which the communication unit 53 receiving the instruction of the low-speed detection period generation instruction unit 78 inserts a low-speed detection period (HIGH signal period) sufficiently longer than the expansion time of the waveform expansion circuit can be considered. ..

As a result, even if a communication device that supports only the old method of low-speed communication and a communication device that supports the new method of high-speed communication exist on the same transmission line, communication can be performed without interference on the transmission line. can. Moreover, since a low-speed detection period that is longer than one character data for high-speed communication can be inserted, higher-speed communication can also be supported.

Next, the equipment communication system of the third embodiment will be described with reference to FIGS. 15 to 17. In the equipment communication system of the above-described embodiment, an example of using pace synchronization and AMI code as a communication method has been described, but in this embodiment, an example of using FSK modulation as a communication method will be described. It should be noted that the points common to the above-described embodiment will be omitted.

As the equipment communication system of the third embodiment, when the modulation / demodulation unit 62 is an FSK (Frequency Shift Keying) modulation method, high-speed communication data cannot be detected by the free channel detection process of the low-speed device, and the problem is solved. The method of inserting the low-speed detection period based on the instruction of the low-speed detection period generation instruction unit 78 will be described.

FIG. 15 is a detailed configuration diagram of a high-speed device of the equipment communication system according to the present embodiment, and FIG. 16 is a detailed configuration diagram of the low-speed device. The same functions as those of the equipment shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

The high-speed device shown in FIG. 15 is provided with a high-frequency low-pass filter (LPF) 901 on the transmitting side of the communication unit and a high-frequency low-frequency passing filter 902 on the receiving side of the communication unit. Further, instead of the modulation / demodulation unit 62 shown in FIG. 3, a low-speed FSK modulation unit 211, a high-speed FSK modulation unit 212, a low-speed FSK demodulation unit 213, and a high-speed FSK demodulation unit 214 are provided. That is, it is a configuration of an LPF through which a low-speed FSK signal can pass for both high-speed communication and low-speed communication. On the other hand, the low-speed device shown in FIG. 16 is provided with a low frequency band pass filter (BPF) 903 on the transmitting side of the communication unit and a low frequency band pass filter 904 on the receiving side of the communication unit. Further, instead of the modulation / demodulation unit 62 shown in FIG. 3, a low-speed FSK modulation unit 211 and a low-speed FSK demodulation unit 213 are provided. Although both FIGS. 15 and 16 do not include the coding unit 61 and the decoding unit 63, they may be configured to include the coding unit 61 and the decoding unit 63.

For example, the transmission unit 72 of FIG. 15 transmits 2.4 kbps transmission data 501 to the low-speed FSK modulation unit 211 during low-speed communication, and transmits transmission data 501 to the high-speed FSK modulation unit 212 at 80 kbps during high-speed communication. The low-speed FSK modulation unit 211 FSK-modulates the transmission data 501 to a 2.4 kHz sine wave for the mark “1” and a 3.6 kHz sine wave for the space “0”, and passes the high frequency low frequency pass filter 901. It is transmitted to the equipment network 5. On the other hand, the high-speed FSK modulation unit 212 FSK-modulates the transmission data 501 to an 80 kHz sine wave for the mark “1” and a 120 kHz sine wave for the space “0”, and passes the high frequency low frequency pass filter 901 through the equipment network. Send to 5. Such a modulation method is also called MSK (Minimum Shift Keying).

On the other hand, the low-speed FSK demodulation unit 213 FSK demodulates the signal received from the equipment network 5 at the carrier frequency for low-speed communication, and notifies the reception unit 73 of the received data 504. The high-speed FSK demodulation unit 214 FSK demodulates the signal received from the equipment network 5 at the carrier frequency for high-speed communication, and notifies the reception unit 73 of the received data 504.

Whether to use the low-speed FSK modulation unit 211 and the high-speed FSK modulation unit 212, the low-speed FSK demodulation unit 213 and the high-speed FSK demodulation unit 214 is based on the instructions of the communication speed switching unit 77 and the low-speed detection period generation instruction unit 78. It can be switched by a switch.

Subsequently, the operation of the free channel detection unit 64 of this embodiment will be described with reference to FIG.

The frequency graph 181 shows the positional relationship between the frequency spectra of the low-speed signal and the high-speed signal in this embodiment. In this embodiment, the spectrum is distributed around fc1 = 2.4 kHz during low-speed communication, and the spectrum is distributed around fc2 = 80 kHz during high-speed communication.

The free channel detection unit 64 of the low-speed device determines the free status of the transmission line by detecting the signal energy of the carrier frequency fc1 using a frequency detection circuit or the like. The free channel detection unit 64 of the high-speed device also determines the free status of the transmission line by detecting the signal energies of the carrier frequency fc1 and the carrier frequency fc2 using a frequency detection circuit or the like.

The frequency graph 182 shows the frequency spectrum when the high-speed signal is received by the free channel detection unit 64 of the high-speed device. The free channel detection unit 64 of the high-speed device removes and receives high-frequency components outside the high-speed signal of the carrier frequency fc2 by the high-frequency low-pass filter 902. In this case, since the high-speed device receives the signal of the carrier frequency fc2, the free channel detection unit 64 determines that the transmission line is in use.

The frequency graph 183 shows a frequency spectrum when a low-speed signal is received by the free channel detection unit 64 of the high-speed device. The free channel detection unit 64 of the high-speed device removes and receives high-frequency components outside the high-speed signal of the carrier frequency fc2 by the high-frequency low-pass filter 902. In this case, since the high-speed device receives the signal of the carrier frequency fc1, the free channel detection unit 64 determines that the transmission line is in use.

The frequency graph 184 shows a frequency spectrum when a low-speed signal is received by the free channel detection unit 64 of the low-speed device. The free channel detection unit 64 of the low-speed device removes high-frequency components and low-frequency components outside the low-speed signal of the carrier frequency fc1 by the low-frequency band pass filter 904 and receives them. In this case, since the low-speed device receives the signal of the carrier frequency fc1, the free channel detection unit 64 determines that the transmission line is in use.

The frequency graph 185 shows the frequency spectrum when the high-speed signal is received by the free channel detection unit 64 of the low-speed device. The free channel detection unit 64 of the low-speed device removes high-frequency components and low-frequency components outside the low-speed signal of the carrier frequency fc1 by the low-frequency band pass filter 904 and receives them. In this case, since the low-speed device cannot detect the signal energy of the carrier frequency fc1, the free channel detection unit 64 determines that the transmission line is free. That is, while the high-speed device is transmitting high-speed communication data, the low-speed device cannot detect the signal energy of the carrier frequency fc1 even if the free channel detection process is performed, and detects that communication is being performed on the transmission path. There will be cases where it cannot be done. Then, the low-speed device may transmit a low-speed signal while high-speed communication is being performed on the transmission path. In that case, the high-speed device that originally wants to receive only the high-speed FSK signal is interfered with by the low-speed FSK signal erroneously transmitted by the low-speed device, as shown in the frequency graph 183.

Therefore, in this embodiment, as described with reference to FIGS. 5A and 5B, interference between the two is prevented by switching between low-speed communication and high-speed communication in a time-division manner. In order to reliably perform time division switching, the high-speed apparatus inserts a low-speed detection period during high-speed communication based on the instruction of the low-speed detection period generation instruction unit 78. Specifically, the FSK signal having the carrier frequency fc1 is transmitted during the low-speed detection period. A signal longer than the shortest time resolution that can be detected by the free channel detection unit 64 of the low-speed device is transmitted. This is performed by the communication unit 53 that has received the instruction from the low-speed detection period generation instruction unit 78.

As a result, the signal energy of the carrier frequency fc1 can be detected by the free channel detection process of the low-speed device, and it is possible to correctly detect that the transmission line is in use. Therefore, even if a communication device that supports only low-speed communication of the old method and a communication device that supports high-speed communication of the new method exist on the same transmission line, communication can be performed on the transmission line without interference. ..

When the low-speed device receives such a signal, the signal flows to the low-speed FSK demodulation unit 213, the reception unit 73, and the reception data analysis unit 74, but the data to be carried on the carrier wave is emptied or specified as an abnormal value. If it is left, it will be interpreted as abnormal data by parity check and CRC and discarded.

When the high-speed device receives the signal, it cannot be demodulated by the high-speed FSK demodulation unit 214 and is discarded as an abnormal signal, so that there is no particular problem.
(Processing flowchart of low speed detection period generation instruction unit 78)
The transmission / reception processing of the equipment in the first to third embodiments will be described with reference to FIGS. 18 to 24.

FIG. 18 is a flowchart showing a transmission / reception process of the low-speed device. In the following, a packet transmitted by low-speed communication is referred to as a “low-speed packet”, and a packet transmitted by high-speed communication is referred to as a “high-speed packet”.

First, in S101, the low-speed device waits for the reception of the low-speed packet, and in S102, the low-speed device determines whether or not the low-speed packet is received. If Yes in S102, proceed to S103, and if No, proceed to S111.

In S103, the low speed device receives the low speed packet, and in S104, the low speed device determines whether or not the received packet is normal. If Yes in S104, proceed to S105, and if No, return to S101.

If the packet is normal, in S105, the low speed device determines whether or not the received packet is destined for itself. When the destination address field 86 of the received packet has its own address or the multicast destination to which it belongs, the received packet is addressed to itself. If Yes in S105, proceed to S106, and if No, return to S101.

In S106, the low-speed device performs processing based on the received packet, and then determines whether or not a response to the received packet is necessary. If Yes in S106, proceed to S107, and if No, return to S101.

In S107, the low-speed device creates ack data for packet response, and in S113, the created ack data is transmitted.

On the other hand, when there is no low-speed reception in S102, in S111, the low-speed device determines whether or not a packet to be transmitted from itself exists. If Yes in S111, proceed to S112, and if No, return to S101.

In S112, the low-speed device performs a process of creating a packet (transmission packet) to be transmitted (details are shown in FIG. 19).

In S113, the low-speed device performs packet transmission processing (details in FIG. 20) for the ack data prepared in S107 or the packet newly created in S112 after the waiting time in the period T3.

FIG. 19 is a flowchart showing details of the transmission packet creation process S112 and the like during high-speed communication and low-speed communication. Here, the operating subject will be described as the equipment of the packet transmission source.

First, in S201, the equipment determines whether or not to create a header for the transmission packet. If Yes in S201, proceed to S202, and if No, proceed to S208. Since the ack and the like shown in FIG. 6 and the like are data having no header, the process proceeds to S208 when creating the data.

In S202, the equipment determines whether or not the destination of the transmission packet is one (multiple units). If Yes in S202, proceed to S203, and if No, proceed to S204. In S203, the equipment, as a unicast, describes the address of one transmission destination in the header column 81 of the transmission packet. On the other hand, in S204, the equipment and equipment describe the addresses indicating a plurality of destinations in the header column 81 of the transmission packet as multicast.

After that, in S205, the equipment determines whether or not a response to the transmission packet is necessary. If Yes in S205, proceed to S206, and if No, proceed to S207. In S206, the equipment requires a response in the communication type column 87 of the transmission packet. On the other hand, in S207, the equipment does not describe the response requirement in the communication type column 87 of the transmission packet. In the communication type column 87, other necessary type values listed in FIG. 4 may be described.

After that, in S208, the equipment determines whether or not to create the data of the transmission packet. This branch is No when only the header column 81 is transmitted in advance. If Yes in S208, proceed to S209, and if No, proceed to S210. In S209, the equipment creates a data column 82 of the transmission packet and a data length column 88 thereof.

Finally, in S210, data division is performed during high-speed communication. This step is omitted during low-speed communication.

FIG. 24 is a diagram illustrating a data division method executed in S210. 301 shows an example of the data structure, and the data string 311 represents the data column 82 which is the original data part created in S209. The data column 312 represents a state in which the data column 311 (data column 82) is divided. If the maximum transmission speed of low-speed communication is known, the maximum data length that can be transmitted in the period T4 can be calculated, so the data is divided so as to be equal to or less than the maximum data length. Here, an example in which the data field 82 is divided into four parts 1 to 4 is shown.

Further, the data string 313 represents transmission packets P1 to P4 in which each divided data is packetized. The header column 81 and the parity column 83 of each packet are the same as those shown in FIG. Here, an example is shown in which a division flag column 321 is further added and used together with the header column 81 as an extension header for a new split packet.

Table 302 shown in Table 4 shows a description example of the division flag column 321. For example, "0x00" is described when the packet is not divided and when the packet contains the final divided data. Further, in the case of a packet containing data having subsequent data in the divided data, "0x01" is described.

FIG. 20 to be described next is a flowchart showing details of packet transmission processing during high-speed communication and low-speed communication.

First, in S221, the equipment and equipment waits for a period (any of T1, T2, and T3) specified by the caller of the flowchart of FIG. 20, and when the carrier is not detected during that period, the equipment network 5 Is vacant and it is judged that communication is possible.

In S222, the insertion process of the low-speed detection period is performed during high-speed communication. Specific examples of this process are as already described in FIG. 10 and the like, and predetermined data is transmitted or a predetermined non-signal period is provided. This step is omitted during low-speed communication.

In S223, the equipment equipment transmits a transmission packet (data) to the equipment network 5. Here, whether to use high-speed communication or low-speed communication is as specified by the caller of the flowchart of FIG.

In S224, the equipment determines whether or not the data of S223 can be transmitted normally. If Yes in S224, proceed to S225, and if No, return to S221. If the data cannot be transmitted normally even if the data is retransmitted multiple times, it is regarded as an abnormal state and the retransmission is terminated.

As S225, if there is untransmitted data such as the remaining packets at the time of division, it returns to S221, and if not, it ends.

FIG. 21 described below is a flowchart showing a reception process of the high-speed device.

First, in S301, the high-speed device waits for the reception of the low-speed packet, and in S302, the high-speed device determines whether or not the low-speed packet has been received. If Yes in S302, the process proceeds to S303, and if No, the process proceeds to terminal B1 (S401 in FIG. 22).

In S303, the high speed device receives the low speed packet. This low-speed packet is, for example, a high-speed trigger for preparing for high-speed communication.

In S304, the high-speed device determines whether or not the received packet is normal. If Yes in S304, proceed to S305, and if No, return to S301. If the packet is normal, in S305, the high speed device determines whether or not a high speed trigger is specified for the received packet. If Yes in S305, the process proceeds to S306, and if No, the process proceeds to terminal A (S105 in FIG. 18). When returning to S101 after executing the process from the terminal A, the process returns to S301 instead of S101.

In S306, the high-speed device determines whether or not the received high-speed trigger has a high-speed communication period designation. If Yes in S306, proceed to S307, and if No, proceed to S311. In S307, the high-speed device starts a high-speed communication counter that measures the high-speed communication period (or the number of high-speed transmission / reception). This counter is constantly monitored separately from the main processing of the flowchart shown in FIG. 21, and the counter is updated so that high-speed communication can be performed within a designated range.

Next, in S311 the high-speed device receives the high-speed packet, and in S312, the high-speed device determines whether or not the received high-speed packet is normal. If Yes in S312, proceed to S313, and if No, proceed to S320. If the packet is normal, in S313, the high-speed device determines whether or not the received high-speed packet is addressed to itself. If Yes in S313, proceed to S314, and if No, proceed to S320.

In S314, the high-speed device determines whether or not a response to the received packet is necessary after performing processing based on the received packet. If Yes in S314, proceed to S315, and if No, proceed to S320.

In S315, the high-speed device creates ack data for packet response, and in S316, the high-speed device waits for the elapse of a predetermined waiting time (period T1 during low-speed communication, period T2 during high-speed communication). Send a "response required" response packet.

After that, in S320, the high-speed device determines whether or not the high-speed communication counter in S307 is currently in the valid period (or the number of valid times). If Yes in S320, proceed to S321, and if No, return to S301. In S321, the high-speed device waits for the reception of the high-speed packet following the previously received high-speed packet, and in S322, the high-speed device determines whether or not the high-speed packet is received. If Yes in S322, the process proceeds to S323, and if No, the process proceeds to terminal B2 (S421 in FIG. 23).

In S323, when the high-speed device receives the high-speed packet, in S324, the high-speed device determines whether or not the received packet is normal. If Yes in S324, it returns to terminal C (S306), and if No, it returns to S320. By repeating these processes while the high-speed period counter is valid, all high-speed packets can be received and necessary data can be restored.

FIG. 22, which will be described next, is a flowchart showing the transmission processing for the first time when the transmission processing of the high-speed device is continuously performed a plurality of times.

First, in S401, the high-speed device determines whether or not a packet transmitted from itself exists. If Yes in S401, the process proceeds to S402, and if No, the process proceeds to terminal D (S301 in FIG. 21).

In S402, the high-speed device determines whether or not high-speed communication is performed. If Yes in S402, the process proceeds to S403, and if No, the process proceeds to terminal F (S112 in FIG. 18). In the flow of FIG. 18, instead of returning to S101, it returns to S301. When performing high-speed communication, in S403, the high-speed device sets a high-speed trigger in the communication type column 87 of the transmission packet.

In S404, the high-speed device determines whether or not to specify the high-speed communication period. If Yes in S404, proceed to S405, and if No, proceed to S406. In S405, the high-speed device sets the high-speed communication period (or the number of high-speed communication) in the data length column 88 of the transmission packet. Further, in S406, the high-speed device creates a transmission packet including the data field 82 of the high-speed trigger (details are shown in FIG. 19).

In the next S407, the high-speed device waits for the waiting time T3, and then transmits the packet created in S406 by low-speed communication (details are shown in FIG. 20). In S411, the high-speed device starts the high-speed communication counter as in S307. If the high-speed communication period is not specified, this step is omitted. In the final S412, the high-speed device transmits a packet by high-speed communication (details are shown in FIG. 20). Then, the process proceeds to terminal E (S320 in FIG. 21) after S412.

FIG. 23, which will be described next, is a flowchart showing the second and subsequent transmission processes of the high-speed device.

First, in S421, the high-speed device determines whether or not there are two or more packets transmitted from itself. If Yes in S421, the process proceeds to S422, and if No, the process proceeds to terminal E (S320 in FIG. 21).

In S422, the high-speed device determines whether or not high-speed communication is performed. If Yes in S422, proceed to S424, and if No, proceed to S423. When high-speed communication is not performed, in S423, the high-speed device waits for the end of the high-speed communication counter, and then proceeds to the terminal F (S112 in FIG. 18). In the flow of FIG. 18, instead of returning to S101, it returns to S301. On the other hand, in the case of high-speed communication, in S424, the high-speed device determines whether or not to review the current high-speed communication period. If Yes in S424, proceed to S425, and if No, proceed to S426.

When reviewing the high-speed communication period, in S425, the high-speed device redesignates the high-speed communication period in the data length column 88 of the transmission packet. This extends the high-speed communication period.

After that, in S426, the high-speed device creates a transmission packet including communication data (details are shown in FIG. 19). Then, in S427, the high-speed device waits for the waiting time T2 and then transmits the packet by high-speed communication (details are shown in FIG. 20). Finally, in S431, the high-speed device starts the reset high-speed communication counter and proceeds to the terminal E (S320 in FIG. 21) as in S411.

In the equipment communication system of the present embodiment described above, even in the equipment network 5 in which the low-speed device and the high-speed device coexist, the high-speed device inserts the low-speed communication detection period, so that the low-speed device is in high-speed communication. This can be detected, and low-speed communication and high-speed communication can be used properly in the same equipment network 5, so that the availability of the system can be improved.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations.

Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.

Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration. Further, each of the above configurations, functions, processing units, processing means and the like may be realized by hardware by designing a part or all of them by, for example, an integrated circuit.

Further, each of the above configurations, functions, and the like may be realized by software by the processor interpreting and executing a program that realizes each function.

Information such as programs, tables, and files that realize each function can be stored in memory, hard disks, recording devices such as SSDs (Solid State Drives), IC (Integrated Circuit) cards, SD cards, DVDs (Digital Versatile Discs), etc. Can be placed on the recording medium of.

In addition, the control lines and information lines indicate those that are considered necessary for explanation, and do not necessarily indicate all the control lines and information lines in the product. In practice, it can be considered that almost all configurations are interconnected.

Further, the communication means for connecting each device may be changed to a wireless LAN, a wired LAN, or another communication means.

5 Equipment network 8a 1st group 8b 2nd group 9 Upper equipment 11,12 Management equipment 21-26 Indoor unit 31,32 Outdoor unit 41,42 Equipment 51 Storage unit 52 Load unit 53 Communication unit 54 Control unit 61 Coding unit 62 Frequency / Demodition Keying 63 Decoding Unit 64 Free Channel Detection Unit 71 Transmission Data Generation Unit 72 Transmission Unit 73 Reception Unit 74 Reception Data Analysis Unit 75 Communication Control Unit 76 Communication Speed Judgment Unit 77 Communication Speed Switching Unit 78 Low Speed Detection Period Generation Instruction Unit 80 Packets Format 81 Header column 82 Data column 83 Parity column 84 Device type column 85 Source address column 86 Destination address column 87 Communication type column 88 Data length column 201 NRZ / RZ conversion unit 202 RZ / NRZ conversion unit 203 Free channel detection unit 211 Low-speed FSK modulation unit 212 High-speed FSK modulation unit 213 Low-speed FSK demodulation unit 214 High-speed FSK demographic unit 321 Division flag column

Claims (9)

A communication unit that can switch between the first communication method and the second communication method of the time-division multiple access method and communicate with each other.
When communicating by the second communication method, the first communication detection period generation instruction unit that instructs the generation of the channel use detection period of the first communication method, and the
Equipped with
The communication unit transmits a signal including the channel use detection period on the transmission path based on the channel use detection period generation instruction from the first communication detection period generation instruction unit .
The communication control device is characterized in that the first communication detection period generation instruction unit issues an instruction to generate the channel use detection period at intervals shorter than the free channel detection execution period of the first communication method. The first communication detection period generation instruction unit is
The communication control device according to claim 1, wherein an instruction to generate the channel use detection period is issued immediately before the communication of the second communication method. A communication unit that can switch between the first communication method and the second communication method of the time-division multiple access method and communicate with each other.
When communicating by the second communication method, the first communication detection period generation instruction unit that instructs the generation of the channel use detection period of the first communication method, and the
Equipped with
The communication unit transmits a signal including the channel use detection period on the transmission path based on the channel use detection period generation instruction from the first communication detection period generation instruction unit.
The communication unit includes a first communication signal detection circuit that detects a signal of the first communication method.
The channel use detection period is longer than the time resolution of the first communication signal detection circuit.
The first communication method is pacing synchronous communication.
The channel use detection period, communication controller you being a transmission period of a signal including a Start bit for the start-stop synchronous communication. The communication control device according to claim 3, wherein the first communication method is communication using AMI modulation / demodulation. The communication unit includes a waveform expansion circuit for RZ / NRZ conversion.
The communication control device according to claim 4, wherein the channel use detection period includes a no-signal period longer than the time constant of the waveform expansion circuit. The communication unit includes a waveform expansion circuit for RZ / NRZ conversion.
The communication control device according to claim 4, wherein the channel use detection period is a transmission period of a signal including a detection bit string longer than the time constant of the waveform expansion circuit. A communication unit that can switch between the first communication method and the second communication method of the time-division multiple access method and communicate with each other.
When communicating by the second communication method, the first communication detection period generation instruction unit that instructs the generation of the channel use detection period of the first communication method, and the
Equipped with
The communication unit transmits a signal including the channel use detection period on the transmission path based on the channel use detection period generation instruction from the first communication detection period generation instruction unit.
The first communication method is communication using FSK modulation / demodulation.
The channel use detection period communication control device you being a transmission period of a signal including a frequency component of the carrier of the FSK modulation and demodulation. A communication unit that can switch between the first communication method and the second communication method of the time-division multiple access method and communicate with each other.
A control unit that transmits unencoded transmission data to the communication unit and receives decrypted reception data from the communication unit.
It is a communication control device equipped with
The control unit is characterized in that when the communication unit communicates by the second communication method, transmission data including a channel use detection signal of the first communication method is transmitted to the communication unit. Control device. A communication unit that can switch between the first communication method and the second communication method of the time-division multiple access method and communicate with each other.
A control unit that transmits unencoded transmission data to the communication unit and receives decrypted reception data from the communication unit.
It is a communication control device equipped with
A communication control device, characterized in that, when communicating by the second communication method, a signal including a channel use detection signal of the first communication method is transmitted on a transmission path.

Images