JPH02277397A - Remote supervisory system - Google Patents

Abstract

PURPOSE:To detect a slave station in which abnormality occurs by sending a general polling signal having bits of all slave stations periodically from a master station, and confirming a signal returned from the slave station. CONSTITUTION:The master station 1 sends out the general polling signal 3 to monitor plural slave stations 21-2n comprehensively. The last terminating station 2n sends out a polling bit corresponding to the one of its own station out of the signals 3 to the slave station 2n-1 nearer next to the master station 1 without inverting when no state change occurs in its own station. Similarly, the slave station 21 inverts the polling bit corresponding to the slave station 23 when the state change occurs in its own station, and sends it to the master station without inverting when no state change occurs. The master station 1 checks the polling bits of the slave stations 21-2n from received signals 3, and judges that no state change occurs when none of bits are inverted.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a remote monitoring system.

[Conventional technology]

Conventionally, this type of remote monitoring method polls each slave station sequentially from the master station, and if a change in status occurs in the slave station specified by polling, it reports the occurrence of the status change.
The master station monitored the status of all slave stations by reporting that the status was normal.

[Problem to be solved by the invention]

The conventional remote monitoring method described above is a method in which the master station polls each slave station, and the total number of slave stations is N, and the master station polls any slave station and sends back a response signal from the slave station. TR5 Time from completion of polling of an arbitrary slave station to start of polling operation of the next arbitrary slave station.

Then, the time T required to complete the polling operation of all slave stations is T=NXTR+(N-1)T.

In the conventional typical example, N-32 station, TR011
If T = 0.05 seconds, then T = 4.75 seconds, which has the disadvantage of increasing the delay time from the occurrence of a state change in the slave station to the detection of the change in the status of the slave station at the master station. .

An object of the present invention is to provide a remote monitoring system that solves the above problems.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a remote monitoring control system having a master station for remote monitoring and a plurality of slave stations for remote monitoring, in which a general polling signal having the same number of bits as Kaneko is periodically sent from the master station. At each slave station, the bit is inverted and sent to the next slave station only when there is no change in the status of the corresponding station, and the master station checks the contents of the signal sent back through all the slave stations. By doing so, it detects the slave station in which an abnormality has occurred, sends a selective polling signal to the slave station again, and detects the detailed status of the slave station based on the selective polling response signal from the slave station. It is.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing main signals in one embodiment of the present invention.

In FIG. 1, a master station 1 of the remote monitoring system according to the present invention periodically sends out a general baud link signal 3 shown in FIG. 2 for collectively monitoring a plurality of slave stations 21 to 2o. Slave station 2 of the final terminal station. , in this case, the polling bit corresponding to the own station in the polling signal 3 will be inverted if there is a state change in the own station by +-1, and if there is a state change, it will not be inverted and will be sent to the next master station 1. The data is sent to the slave station 21-1, which is close to the mobile station 21-1. Similarly, the slave station 21 inverts the polling bit corresponding to the slave station 2□ if there is a state change within the local station.
If not, it is sent to the master station without inversion.

Regarding the general baud link signal 3 that was received by the master station 1,
Child station 2. The polling pin 1 of ~2n is checked, and if all bits are inverted, it is determined that there has been no change in the status of any slave station, and the general polling signal 3 is again sent to the slave stations 2 and ~2fi. On the other hand, if the polling bit of the station is not inverted, the selection baud link signal 4 shown in FIG. 2 is sent to the corresponding slave station. The slave station designated by the selective polling signal 4 sends back the state within itself to the master station 1 by the selective polling response signal 5 shown in FIG. The master station 1 obtains the detailed status of the corresponding slave station by decoding the contents of the selective polling response signal 5. In addition, the master station 1
If the polling response signal 5 is not received from the corresponding slave station within a certain period of time after the selective polling signal 4 is sent, it can be determined that there is a failure in the monitoring device of the corresponding slave station.

Each slave station detects the downlink general polling signal from the master station, and if it does not receive the uplink general polling signal within a predetermined time, it generates a general polling signal at its own station, and This handles failures in some slave stations. Additionally, each slave station has a function of forcibly passing the uplink and downlink monitoring control lines in the event of a failure in the monitoring equipment within the local station.

〔Effect of the invention〕

As explained above, in the present invention, the polling operation completion time T' of all slave stations is T'=TR+T.

In the typical example mentioned above, it can be T'0.15 seconds, so the delay time from the state change at the slave station until the master station detects the state change at the slave station. This has the effect of making it shorter.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing main signals. 1... Master station 21-2. ,...Slave station 3
...General polling signal 4...Selective polling signal 5...Selective polling response signal

Claims (1)

[Claims] (1) In a remote monitoring control system having a master station for remote monitoring and a plurality of slave stations for remote monitoring, the master station periodically sends out a general polling signal having bits for all slave stations,
In each slave station, the bit is inverted and sent to the next slave station only when there is no change in the status of the corresponding station, and the master station checks the contents of the signal sent back through all the slave stations. It is characterized by detecting a slave station in which an abnormality has occurred, sending out a selective polling signal to the slave station again, and detecting the detailed status of the slave station based on the selective polling response signal from the slave station. A remote monitoring method.