JPS63299597A - Supervisory information transmitter - Google Patents

Abstract

PURPOSE:To immediately inform the change of the state of supervisory information by transmitting an invitation signal without any specification of a station from a master station, allowing branch stations which detect the change of the state of the supervisory information to independently transmit in response to that according to the response delay time of the N pieces of discrete response delay time group and reducing the probability of the scramble of a circuit. CONSTITUTION:A response delay time setting part 6 setting the optional response delay time among the N pieces of discrete response delay time group previously set at the detecting time of the change of the state at random, an other station response detection part 7 detecting the existence of the response from the other station and a transmission control part 8 controlling to start the transmission of a response signal after the response delay time elapsing when it receives the invitation signal without the specification of the station and controlling to postpone the response signal of an intra-station until the reception time of a next invitation signal before the response delay time and when the response of the other station is detected in the course of transmitting the response signal are provided with the branch station side. Thus the change of the state of the supervisory information can be informed to the master station from the branch station by the invitation signal without the specification of the station and the scramble of the circuit can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to a system for transmitting monitoring information using a polling format, and particularly to a monitoring information transmitting device on the slave station side thereof.

[Prior Art] Conventionally, this type of device has a block configuration as shown in FIG. Based on the processing result of the monitoring information processing unit 2, the status change detection unit 3 stores whether there is a status change from 5 and sends back a response signal. Further, the master station sends a next invitation signal to all slave stations of the system according to the preset 11 station designation, and collects monitoring information by receiving the response signal.

[Problems to be solved] In the conventional information transfer described above, when the number of slave stations increases, the cycle time required for the master station to collect information from all the slave stations in order to sequentially call and respond to the slave stations increases. There was a problem in that this lengthened the time, making it difficult for the master station to quickly detect changes in the status of the slave stations.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to enable each slave station to promptly notify the master station of changes in the status of monitoring information using solicitation signals without station designation, and to transmit monitoring information without causing line contention. The goal is to provide equipment.

[Means for Solving Problems 1] In order to solve the above-mentioned problems, in the present invention, in addition to the general solicitation signal with a station specification in the solicitation signal from the master station, a solicitation signal without a station specification is provided, When receiving this signal,
To enable any slave station that has detected a state change to send a response signal, and to prevent line contention among multiple slave stations, the slave station must begin transmitting a response signal from the time it receives the solicitation signal. It is now possible to randomly set the time until the start of transmission (hereinafter referred to as response delay time).

In other words, when detecting a state change, the preset N
a response delay time setting section that randomly sets an arbitrary response delay time from a group of discrete response delay times; another station response detection section that detects the presence or absence of a response from another station; When a solicitation signal with no station designation is received, the transmission of the response signal is controlled to start after the response delay time determined by the response delay time setting section has elapsed, and the transmission of the response signal is controlled to start before the response delay time and while the response signal is being transmitted. When a response is detected, a transmission control section is provided at the branch station to control the response signal of the own station until the next solicitation signal is received, thereby configuring the monitoring information transmission apparatus.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block circuit diagram of a monitoring information transmission device showing one embodiment of the present invention. Of the members shown in the figure,
Components having the same functions as those shown in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the device of this embodiment, code receiving section 1. Monitoring information processing unit 2.
In addition to the status change detection section 3 and the code transmission section 5, a response delay time setting section 6 and another station response detection section 7 are provided, and in place of the conventional transmission control section 4, a solicitation signal without station specification is received. A transmission control unit 8 having a transmission control function in case of the above is provided on the slave station side.

When the response delay time setting section 6 receives a solicitation signal that does not specify a station, the slave station starts transmitting a response signal from the time when the reception of the solicitation signal ends, in order to prevent a plurality of slave stations from competing for the line. The response delay time is set randomly.

The other station response detection section 7 always detects whether there is a response from another slave station to the master station.

The transmission control unit 8 executes the conventional transmission control when receiving a solicitation signal with a station designation, and also executes the following control when receiving a solicitation signal without a station designation. Become. That is, when a solicitation signal without a station designation is received from the master station, the transmission of the response signal from the own station is stopped after the response delay time determined by the response delay time setting section 6 has elapsed from the end of receiving the solicitation signal. Start control. Furthermore, if a response from another station is detected by the other station response detection section 7 during the response delay time and while transmitting the own station response signal, the transmission of the response signal is stopped when the next solicitation signal is received. It is designed to be deferred until then.

The operation of the device configured as above will be explained.

The solicitation signal from the master station is received by the code receiving unit 1, and if the solicitation signal has a station specification and the own station is specified, the code transmitting unit 5 is driven under the control of the transmission control unit 8. The operation of sending out the response signal is the same as before.

In addition to the above-mentioned operation, in the device of this embodiment, a solicitation signal without station designation is transmitted from the master station to each slave station.

When a solicitation signal with no station specification is received, if the condition change detection section 3 has not detected a change in condition by that point, it will not respond, and if it has detected a change in condition, the response delay time setting section will respond. 6
randomly sets an arbitrary time from among the N discrete response delay time groups and transmits it to the transmission control section 8. Transmission control section 8
waits for this response delay time from the end of receiving the solicitation signal, and if the other station response detection section 7 has not detected a response from another station, it drives the code transmission section 5 and detects the response signal of the own station. Start sending. Furthermore, if the detection unit 7 detects a response from another station during this response delay time, the transmission control unit 8 postpones the response from the own station until the next solicitation signal without station designation is received. It works like this. Furthermore, even if multiple slave stations select and set the same response delay time from N response delay times, the other station response detector 7
The transmission control unit 8 operates so as to immediately interrupt transmission and postpone the response until receiving the next solicitation signal without station designation, and sets the response delay time so that the response delay time is set randomly again. Section 6 operates. Therefore, confusion caused by competition for lines can be prevented.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, although the setting of solicitation signals from the master station may be arbitrary, monitoring information can be collected effectively by alternately repeating solicitation signals with station designations and solicitation signals without station designation.

[Effects of the Invention] As explained above, the present invention allows the slave stations that transmit a solicitation signal without station designation from the master station and detect a change in status to independently respond to N discrete response delay time groups. By randomly setting any one of them and having the response transmitted according to the response delay time, the probability of line contention is minimized and changes in the status of monitoring information are quickly notified to the master station. It has the effect of Furthermore, even if multiple slave stations set the same response delay time and start sending a response, the device is equipped with a response detector for other stations, which will interrupt the transmission and wait until the next solicitation. However, since the response delay time is again set randomly, it has the effect of preventing system confusion due to line contention.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing one embodiment of the present invention, and FIG.
The figure is a block circuit diagram of a conventional device. 6... Response delay time setting section, 7... Other station response detection section, 8... Transmission control section.

Claims (1)

[Claims] In a monitoring information transmission device that transmits monitoring information between a master station and a plurality of branch stations by a polling method, a response delay time setting section that randomly sets an arbitrary delay time from among N discrete delay time groups; , another station response detection unit that constantly detects the presence or absence of a response from another station, and when a solicitation signal without station designation from the master station is received, the response delay time setting unit determines the response delay time from the time when the reception of the solicitation signal ends. control to start transmitting a response signal from its own station after the specified response delay time has elapsed,
If a response from another station is detected by the other station response detection section during this response delay time and while transmitting the own station response signal, the transmission of the response signal is changed to the reception of the next solicitation signal. 1. A monitoring information transmission device characterized in that a transmission control unit for performing deferred control until the end of the period is provided at a branch office.