JPH0646829B2 - Time division multiplex transmission system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a time division multiplex transmission system in which a distributed processing function is added to a centralized control system by a polling system.

[Background Art] In the conventional time-division load control system by the polling method, the function of each terminal is relatively simple and the cost is low, and the user can easily increase the number of loads by purchasing additional terminals. However, on the other hand, it is extremely difficult to upgrade the system function after the delivery and installation because it is necessary to change the program of the base unit. On the other hand, in the distributed control method in which all terminals have the same functions as the master unit, the system functions can be improved by simply connecting terminals with the required functions to the line even after delivery and installation. Since the terminal has the function of the base unit, it becomes complicated both in terms of hardware and software, and there is a drawback that the cost of the entire system increases.

[Object of the Invention] The present invention has been made in view of the above problems, and an object of the present invention is to use a centralized control system and a distributed control system together to provide a distributed processing function to an arbitrary terminal device. The addition is to provide a transmission method that can improve or add a system function without significantly increasing the cost.

DISCLOSURE OF THE INVENTION However, in the time division multiplex transmission method according to the present invention, polling is performed from a master unit to a plurality of terminal units via a transmission line by a control signal which is a voltage signal including a terminal unit address and transmission data. In the two-way transmission system of the method of returning the return signal, which is a current signal including the return data section, to the master unit, the terminal device receiving the mode signal at the beginning of the return signal distinguishes the normal processing mode from the distributed processing mode. In addition to adding the mode signal of the distributed processing mode, the return data part of the return signal includes the address of the terminal device to which the data should be transmitted by the distributed processing and the transmission data, and when the parent device receives the return signal of the distributed processing mode. The polling may be temporarily stopped, and the return data part of the return signal may be converted from a current signal to a voltage signal and retransmitted as a control signal. Therefore, by including the terminal address and the transmission data in the return signal of the distributed processing mode, the distributed processing terminal controls other terminals or sends data without the control program of the master unit. It is characterized in that it can be exchanged. That is, when a terminal device performs distributed processing such as controlling another terminal device, when the terminal device is polled by the master device, the terminal device address and transmission data of the destination terminal device that transmits data are transmitted. By sending back the return signal of the distributed processing mode including and, the base unit only sends the return data part of the return signal after converting the current signal to the voltage signal and sends it It is possible. Therefore, if the terminal device sends the return signal in the distributed processing mode once, the transmission data included in the return signal can be transmitted to another terminal device through the master device. This means that for distributed processing terminals, it is only necessary to make a change to add the function of adding a mode signal to the return signal to a normal terminal, and this can be easily handled by changing the software. In addition, it is only possible to provide a function to perform processing corresponding to the distributed processing mode on the master unit, and there is no need to change the hardware substantially for a bidirectional transmission system that does not have the distributed processing function. It can be easily implemented.

[Embodiment] FIG. 1 is a block circuit diagram showing the overall configuration of the method of the present invention, in which a master device 1, a general terminal device 2 and a distributed processing terminal device 3 are connected to a transmission line 4. As shown in FIG. 2, a return signal is returned from the terminal unit whose address matches the control signal from the master unit. The distributed processing terminal device 3 also operates in the same manner as the general terminal device 2.
As shown in the figure, assuming that the distributed processing terminal device 3 is connected to the address 3, the master device 1 in the polling operation
From address 1 → address 2 → address 3 → ...
All addresses including the distributed processing terminal 3 are cyclically accessed, such as → address n → address 1.

FIG. 4 shows the format of the control signal and the return signal at the time of polling. The polling signal is a mode signal for distinguishing between the normal mode and the distributed processing mode by "0" or "1", the terminal address, It consists of a byte counter that indicates the data length of the next transmission data section, a transmission data section that contains control information to the terminal, and checksum data for checking transmission errors of the entire control signal.The return signal is the mode signal. , A byte counter, return data for returning the load status and the status of various monitoring sensors, and a checksum. Fig. 5 shows an example of the signal waveform from the base unit. The long pulse width is data "1", the short pulse width is data "0", and the return signal from the terminal in current mode is also used. The same signal waveform is used.

As shown in FIG. 6, the master unit 1 is composed of a logic unit 11 having a built-in CPU, an operation unit 12 including a keyboard, and a driver unit 13 for transmitting and receiving signals.
In 1 is programmed the polling sequence and cycle, and the transmission or display of control signals to be performed according to the return signals from each terminal, and the master unit manages the entire system. As shown in FIG. 7, the terminals 2 and 3 include a logic unit 21, an operation unit 22, a driver unit 23,
The output unit 24 includes the output unit 24, and the received transmission data is judged by the CPU of the logic unit 21.
Via external device control, monitoring sensor status monitoring,
Alternatively, the information is displayed and the sensor information or the like is returned as reply data during the reply waiting period. The data input from the operation unit 22 is also sent to the parent machine as a return signal.

FIG. 8 shows a circuit configuration of the driver unit 13 of the master unit 1, and when transmitting a transmission signal, a voltage signal whose polarity is inverted by the driver transistors Q ₁ , Q ₂ , Q ₃ , Q ₄ and the inverter IV _{1 is} generated. The signal is sent to the signal line, and when the return signal is received, the current signal is converted into a voltage signal by the comparator CP ₁ and the current detection resistor Rs, and the voltage signal is output to the logic unit 11.

FIG. 9 shows the circuit configuration of the driver unit 23 of the terminals 2 and 3, and when a signal is received, the voltage change of the signal line is converted to a logic level by the comparator CP ₂ and output to the logic unit 21. At the time of reply, the transistor Q ₅ is turned on / off by the reply signal input from the logic section 21 to change the impedance between the signal lines and sent back to the master as a current signal. Further, the power consumption of the terminal is small, and the diode bridge DB receives the power supply by rectifying and smoothing the line voltage.

FIG. 10 is an explanatory view of the distributed processing means which is the main part of the present invention. In the figure, when the distributed processing terminal device 3a wants to control the terminal device 3b by its own program instead of the control program of the master device 1, the master device 1 is simply used as a repeater and the control contents are controlled. Along with the address of the terminal device to be sent, it is sent to the master unit 1 as a return signal b to the polling signal, and when the master unit 1 detects that the mode signal is "1", the sending of the next polling signal is temporarily stopped and this The return data portion of the return signal (i) is converted from the current mode to the voltage mode, and this is retransmitted as the control signal (b).

FIG. 11 shows the format of the return signal at the time of distributed processing, and the return data section at this time is created in the same format as the polling signal shown in FIG. Therefore, the terminal device 3b is substantially controlled by the terminal device 3a, as shown in FIG. The mode signal in the reply data is used by the terminal 3b that has received the control signal from the master unit 1 to distinguish whether it is a normal polling signal or a distributed processing signal. , Terminal 3a using the format of FIG.
You can send back the reply data to. The mode signal in the reply data section or the mode signal in the polling signal is not always necessary, and the mode information may be written in the transmission data section in FIG. 11, for example.

FIG. 12 is a flow chart showing the processing means of the return signal in the master unit 1, which can be easily constructed by hardware. When the master unit receives the return signal from the terminal device for polling, it determines whether the mode signal bit is "1" or "0", and if it is "0", it continues polling to the next address and If so, the reply data portion is retransmitted as a control signal, and the next return signal is awaited. If the next return signal is "mode 1", the reply data section is retransmitted in the same manner, so that the distributed processing terminal can immediately receive a reply to the control signal.

[Advantages of the Invention] According to the above configuration, when a terminal device performs distributed processing such as controlling another terminal device, when the terminal device polls the terminal device, the other party transmitting data Since the return signal of the distributed processing mode including the terminal address of the terminal device and the transmission data is returned, the parent device only converts the return signal portion of the return signal from the current signal to the voltage signal and sends it. The transmission data can be sent to the other party's terminal device. Therefore, if the terminal device sends the return signal in the distributed processing mode once, the transmission data included in the return signal can be transmitted to another terminal device through the master device. In other words, with regard to the distributed processing terminal, it is only necessary to make a change to give the function of adding the mode signal to the return signal to the normal terminal, and it is possible to easily deal with the degree of software change. At the same time, the main unit is only provided with the function of performing the processing corresponding to the distributed processing mode, and it is not necessary to change the hardware substantially for a bidirectional transmission system that does not have the distributed processing function. It has the advantage that it can be implemented. For example, if there is a request to upgrade the control function after the system is delivered and installed, all that is required is to add a terminal with a distributed processing function. There is an advantage that it is not necessary to rewrite the ROM, and since the distributed processing method can be used together at low cost, there is an advantage that the range of use of this type of transmission system can be significantly expanded.

[Brief description of drawings]

FIG. 1 is an overall block diagram of a system showing an embodiment of the present invention, FIGS. 2 and 3 are operational explanatory diagrams of the same, FIG. 4 is a signal format diagram in a normal operation of the same, and FIG.
Fig. 6 is a signal waveform diagram of the same as above, Fig. 6 is a block diagram of the master unit of the above, Fig. 7 is a block diagram of the terminal unit of the same as above, a block circuit diagram showing a configuration of a distributed control terminal, and Fig. 8 is a block diagram of the master unit. FIG. 9 is a circuit configuration diagram of the driver unit, FIG. 9 is a circuit configuration diagram of the driver unit of the terminal device, and FIG. 10 is an operation explanatory diagram of the system during distributed processing,
FIG. 11 is a format diagram of a return signal at the time of distributed processing, and FIG. 12 is a flowchart showing a return signal processing operation of the master unit. 1 is a master unit, 2 is a normal terminal device, 3 is a distributed processing terminal device, 4
Is a transmission line.

Claims (1)

[Claims] 1. A master unit polls a plurality of terminals via a transmission line with a control signal, which is a voltage signal including a terminal address and transmission data, and the polled terminal receives a current including a return data section. In a two-way transmission system in which a return signal, which is a signal, is returned to the master unit, a mode signal for distinguishing between the normal processing mode and the distributed processing mode is added to the beginning of the returned signal, and a mode signal for the distributed processing mode is added. The reply data part of the returned signal includes the address of the terminal device and the transmission data to which the data should be transmitted by the distributed processing, and when the parent device receives the return signal of the distributed processing mode, it temporarily stops polling and returns the returned signal. A time division multiplex transmission system characterized in that the data section is converted from a current signal into a voltage signal and retransmitted as a control signal.