JPH0821892B2 - Wireless communication system - Google Patents

Abstract

PURPOSE:To avoid useless transmission and to reduce the power consumption by giving an inquiry about each slave station from a master station as to whether there is any state change in each slave station in a short period and requesting each slave station as to the present state in a long period. CONSTITUTION:A timer for a short period and a timer for a long period are provided on a timer circuit 106 of a master station, a control circuit 101 sets the timer for a short period, form which a transmission instruction is outputted while a slave station or a relay station is designated to a signal transmission circuit 102. The circuit 102 generates an inquiry signal and sends it, a reply signal reception circuit 103 receives a reply from the slave station on a repeater, if any, and informs it to the control circuit 101. The circuit 101 activates the long period timer and uses a transmission circuit 104 so as to send a state request signal to the slave station or the repeater sending a reply signal, the slave station or the repeater operates a state change monitoring circuit 206 and when the result of monitor is addressed in its own station, it is stored in a storage circuit 207 and the content is sent to the master station.

Description

Description: TECHNICAL FIELD The present invention relates to a wireless communication system mainly composed of a master station, and more particularly to a technique for monitoring slave stations and relay stations.

(Prior Art) A wireless communication system often has a relay station, and is configured as shown in FIG. 7, for example. That is, it is composed of a master station 71 and a plurality of slave stations 73, 73, ... And a relay station 72 which are scattered around the master station 71.

In a wireless communication system mainly composed of this type of master station, a system in which the master station monitors the states of slave stations and relay stations is adopted. A conventional monitoring system is as shown in FIG. 8, for example. ing. In FIG. 8, the master station sets a short cycle timer for about several seconds (step 81) and transmits a status request signal to a certain station (slave station or relay station) (step 81).
82). Then, when the status signal from the corresponding station is received (step 83), a predetermined process is performed for the status signal, and after a lapse of a specified time, the process returns to the previous step 81. On the other hand, when the status signal from the corresponding station is not received (step 83) and the status elapses for the specified time (step 84), abnormality processing is performed and the process returns to the previous step 81. Then do the same for the next station and do it for all stations.

On the other hand, when the slave station or relay station receives the status request signal for its own station (step 85), it collects the status of each part in its own station regarding whether or not an alarm has been issued and whether it is normal, etc. Is transmitted (step 86).

(Problems to be Solved by the Invention) However, in the conventional monitoring method described above,
The master station sends a request to each station in a short cycle, and each station sends the status of its own station to the master station in a short cycle. In this case, even if the status of its own station is normal without alarm status. You will have to respond to the station. In this case, since the own station is called frequently, there is unnecessary power consumption. This issue is important because, for example, stations in remote areas may be forced to rely on battery power.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a wireless communication system in which a master station can monitor each station without causing unnecessary power consumption in a slave station or a relay station. To provide.

(Means for Solving the Problems) In order to achieve the above object, the wireless communication system of the present invention has the following configuration.

That is, the wireless communication system of the present invention is a wireless communication system including a master station and a plurality of slave stations, or a master station and a plurality of slave stations and one or more relay stations; Means for transmitting an inquiry signal to each station and collecting a response signal; means for transmitting a status request signal to a station that responded to the inquiry signal of the short cycle and collecting a status signal; Means for transmitting a status request signal to each station and collecting the status signal; the slave station and the relay station monitor the status change of the local station and store and hold the monitoring result; and the reception of the inquiry signal. And means for returning the response signal only when there is a change in the state of its own station;
Means for returning the status signal indicating the status of the own station in response to the reception of the status request signal;

(Operation) Next, the operation of the wireless communication system of the present invention configured as described above will be described.

The slave station and the relay station constantly monitor the status change of the self station and store and retain the monitoring result. Then, in response to a short cycle inquiry signal of the master station, a response signal is sent back to notify that fact when there is a status change in the local station, and the content of the status change in the local station is sent by the status signal transmitted after that. Let me know. As a result, the master station can know the station in the alarm state.

On the other hand, in response to the status request signal from the master station, not only the station that has changed its state, but also the station that is in a good state with no state change notifies its own state by the state signal. This allows the master station to know the state of the station that did not return a response to the inquiry signal of a short cycle, that is, whether or not the response could not be returned due to a device failure.

In this way, the master station can perform correct monitoring, and the slave station or relay station in a good state does not perform unnecessary transmission, and power consumption can be reduced.

(Examples) Examples of the present invention will be described below with reference to the drawings.

The master station for implementing the monitoring system in the wireless communication system of the present invention is configured as shown in FIG. 1, and the slave station (relay station) is configured as shown in FIG. 2, for example.

In FIG. 1, the master station includes a control circuit 101, an inquiry signal transmission circuit 102, a response signal reception circuit 103, a status request signal transmission circuit 104, a status signal reception circuit 105, a timer circuit 106, and a duplexer. Basically, 107, receiver 108, decoder 109, transmitter 110, encoder 111, and antenna 112 are provided.

In FIG. 2, the slave station (relay station) is a control circuit.
201, an inquiry signal receiving circuit 202, and a response signal transmitting circuit
203, a status request signal receiving circuit 204, and a status signal transmitting circuit
205, a state change monitoring circuit 206, a storage circuit 207, a duplexer 208, a receiver 209, a decoder 210, an encoder 211, a transmitter 212, and an antenna 213 are basically provided.

Next, the monitoring system of the present invention will be described with reference to FIGS.

The timer circuit 106 of the master station is provided with a timer for short cycle and a timer for long cycle, and the master station monitors short cycle (Fig. 4) and long cycle (Fig. 5) based on these timers. ) And long and short cycle combined monitoring (Fig. 6).

First, in FIG. 4, in the master station, the control circuit 101 sets a timer for a short cycle, and the inquiry signal transmission circuit 102
In response to the designated station (slave station or relay station), a transmission command is output (step 400). In response to this, the inquiry signal transmission circuit 102 creates an inquiry signal including the identification number of the corresponding station and the display (type A) of the inquiry signal as shown in FIG. The encoder
Since it is output to 111, the inquiry signal is transmitted from the antenna 112 via the encoder 111, the transmitter 110, and the duplexer 107 (step 401). Then, when the slave station (relay station) transmits a response signal, the response signal is received by the response signal receiving circuit 103 via the antenna 112, the duplexer 107, the receiver 108, and the decoder 109, and that effect is sent to the control circuit 101. Since the notification is given, the control circuit 101 performs an operation of determining whether or not there is a reception notification from the response signal receiving circuit 103 after the command is output (step 40
2). If there is no reception notification within the specified time, the determination result of step 402 is negative (NO), the process returns to the previous step 400, the next applicable slave station (relay station) is designated, and a transmission command is inquired to the signal transmission circuit 102. Output. On the other hand, if there is a reception notification within the specified time, the determination result of step 402 is affirmative (YES).
Therefore, the process proceeds to the next step 403, and the control circuit 101 issues to the state request signal transmission circuit 104 an instruction to transmit the state request signal (FIG. 3 (a) (2)) to the corresponding station that has returned the response signal. Output. As a result, the state request signal transmission circuit 104
The state request signal (identified by type B in FIG. 3 (a) (2)) created by the above is transmitted via the encoder 111, the transmitter 110, the duplexer 107, and the antenna 112.

Thus, the status signal (state (b) (2) in FIG. 3) transmitted by the slave station (relay station) is transmitted to the status signal receiving circuit 105 via the antenna 112, the duplexer 107, the receiver 108, and the decoder 109. (Step 404), the control circuit 101 receives the status signal and performs a predetermined process, and returns to the previous step 400 after waiting a lapse of a specified time, and then to the next applicable slave station (relay station). Control of.

On the other hand, in the slave station (relay station), the control circuit 201 controls the state change monitoring circuit 206 to monitor whether or not an alarm or the like has occurred in each part of the local station, and stores the monitoring result in the storage circuit 207. On the other hand, (step 410), in parallel with this, the determination operation of step 411 is performed. The inquiry signal relating to the master station transmission is the antenna 213, the duplexer 208, and the receiver 20.
9. The inquiry signal receiving circuit 202 via the decoder 210 receives and decodes the signal, and if it is addressed to its own station, a reception notification is output to the control circuit 201.

As a result, the determination result of step 411 becomes affirmative (YES), and then the control circuit 201 accesses the storage circuit 207 to read the stored contents and determines whether or not there is a state change (step 412). If the judgment result is negative (NO),
In other words, if it is in a good state, the process returns to the previous step 410, and concentrates on the regular self-station monitoring operation. On the contrary, if the determination result is affirmative (YES), that is, if an alarm or the like has occurred, a transmission command is output to the response signal transmission circuit 203 to notify the master station of the alarm. As a result, the response signal transmission circuit 203 creates a response signal (FIG. 3 (b) (1)), which is the encoder.
It is transmitted via the 211, the transmitter 212, the duplexer 208, and the antenna 213 (step 413). On the other hand, when the master station transmits a status request signal ((a) (2) in FIG. 3), it is sent to the status request signal receiving circuit 204 via the antenna 213, the duplexer 208, the receiver 209, and the decoder 210. If it is addressed to its own station, it is notified to the control circuit 201, so the control circuit 201 makes the determination in step 414 after the command is output, and the state request signal reception circuit 204 Wait for receipt notification. Then, when there is a reception notification, the determination result of step 414 becomes affirmative (YES), and the control circuit 201 sends a transmission command with the current state of its own station whose state has changed to the state signal transmission circuit.
Output to 205. As a result, the status signal transmission circuit 205 creates a status signal (FIG. 3 (b) (2)), which is the encoder.
It is transmitted via the 211, the transmitter 212, the duplexer 208, and the antenna 213 (step 415). The control circuit 201 continues the in-station monitoring operation (step 410).

In the above short-cycle monitoring operation, the master station can recognize a station that has changed status such as an alarm state, but responds due to device failure such as transmitter failure, receiver failure or power down. It is possible that there are child stations (relay stations) that cannot be returned. Therefore, the master station performs a long cycle monitoring operation as shown in FIG.

In FIG. 5, in the master station, the control circuit 101 sets a long cycle timer, and the status request signal transmission circuit 104 designates the corresponding station (slave station or relay station) and outputs a transmission command (step 500).

As a result, a status request signal to the corresponding station (Fig. 3 (a))
(2)) is transmitted (step 501), the control circuit 1
In 01, it is determined whether or not a status signal (FIG. 3 (b) (2)) is received (step 502), and if the determination result is affirmative (YES), it is determined that the corresponding station is normal, Returning to step 500, the process proceeds to the monitoring of the next applicable station. If the judgment result is negative (NO), the station is recognized as abnormal,
Wait for the specified time to elapse (step 503), then step 500
Go back to and do the same.

 The master station performs the above operation for all stations.

On the other hand, when the slave station or relay station receives the status request signal for itself (FIG. 3 (a) (2)) (step 50)
6), collects the status of each part in the own station regarding the presence / absence of alarm occurrence, normality, etc., and transmits a status signal (Fig. 3 (b) (2)) indicating the current status of the own station ( Step 50
7). In short, the slave station and the relay station respond to the status request signal from the master station by the response signal (Fig. 3 (b)).
Regardless of whether or not (1)) is returned, that is, whether or not there is a status change in the own station, the status signal (Fig. 3 (b)) is always used.
(2)) is returned.

The short cycle monitoring operation and the long cycle monitoring operation described above can be performed in parallel, for example, as shown in FIG. A brief description will be given below.

The master station sets the long cycle timer (step 60
0), transmits a status request signal to the relevant station and collects status signals from the relevant station (step 601), sets a short cycle timer (step 602), and transmits an inquiry signal to the relevant station (step 603). . Then, it is determined whether or not there is a response to the transmission of this inquiry signal (step
If the determination result is affirmative (YES), a status request signal is transmitted to the corresponding station and the status signal is collected (step 60).
5) Go to step 607. On the other hand, if the determination result is negative NO), the loop of step 606 → step 604 waits for the lapse of the specified time, and if no response signal is received within this period, the process similarly proceeds to step 607.

In step 607, the elapse of a specified period of a long cycle is monitored, and within this period, the short cycle monitoring operation of steps 602 to 606 is repeatedly performed to certify the station that has changed its state. After this period, step 60
Returning to 0, step 601 is executed for the next relevant station, and the above is performed for all stations.

On the other hand, the slave station (relay station) performs the following in parallel with the status monitoring of its own station (step 608). That is, step 609
When it is determined that the status request signal has been received, the status signal is transmitted (step 613). This is a response to a long cycle monitoring operation. If it is not determined in step 609 that the status request signal is received, step 61
0, the same 611 judgment is made, the inquiry signal is received, and
When the status change occurs in the own station, a response is returned (step 612). On the other hand, since the status request signal is transmitted (step 609), the status signal is transmitted (step 61).
3). This is a response to the short cycle monitoring operation.

(Effects of the Invention) As described in detail above, according to the wireless communication system of the present invention, each station is queried as to whether or not there has been a state change such as the occurrence of an alarm condition in a short cycle, and each station is currently in a long cycle. Since it is possible to monitor each station in the same way as in the past, since only the station whose status has changed will transmit to the master station when inquiring in a short cycle, there is no wasteful transmission. There is an effect that it is possible to reduce power consumption.

[Brief description of drawings]

1 is a block diagram of a master station according to an embodiment of the present invention, FIG. 2 is a block diagram of a slave station (relay station) according to an embodiment of the present invention, and FIG. (A)) and slave station relay station (FIG. (B)) transmission signal format, fourth
FIG. 5 is a flowchart of a short cycle monitoring operation, FIG. 5 is a flowchart of a long cycle monitoring operation, FIG. 6 is a flowchart when a long cycle and a short cycle are used together, and FIG. 7 is a flowchart of a wireless communication system targeted by the present invention. FIG. 8 is a block diagram of the configuration and is an operation flowchart of the conventional monitoring method. 71 …… Master station, 72 …… Relay station, 73 …… Slave station, 101,201 ……
Control circuit, 102 ... inquiry signal transmission circuit, 103 ... response signal reception circuit, 104 ... state request signal transmission circuit, 105 ...
Status signal receiving circuit, 106 ... Timer circuit, 107,208 ... Common device, 108,209 ... Receiver, 109,210 ... Decoder, 110,21
2 ... Transmitter, 111, 211 ... Encoder, 112, 213 ... Antenna, 202 ... Interrogation signal receiving circuit, 203 ... Response signal transmitting circuit, 204 ... Status request signal receiving circuit, 205 ... Status signal transmitting circuit, 206 ... Status change monitoring circuit, 207 ... Memory circuit.

Claims (1)

[Claims] 1. A wireless communication system comprising a master station and a plurality of slave stations, or a master station and a plurality of slave stations and one or more relay stations; the master station asks each station in a short cycle. Means for transmitting a signal and collecting a response signal; means for transmitting a status request signal to a station that responded to the inquiry signal in the short cycle and collecting a status signal; status request for each station in a long cycle Means for transmitting a signal and collecting a status signal; the slave station and the relay station monitor the status change of the local station and store and hold the monitoring result; and a local station for receiving the inquiry signal. A radio comprising: means for returning the response signal only when there is a status change; and means for returning the status signal indicating the status of the own station upon receipt of the status request signal. Communications system.