JPH02136905A - Supervisory method for programmable controller - Google Patents

Abstract

PURPOSE:To early detect the abnormality of a programmable controller by increasing the supervisory time by an amount equal to the time monitor performed after the initial transmission having an idle transmission interval and shortening the supervisory time in a normal state. CONSTITUTION:A programmable controller 2 of a stored program system owns the only initiative to a transmission line 1 and contains a control program. An input/output device 3 owns a transmission function to perform the transmission of data in accordance with the controller 2 connected to the line 1 and performs the transfer of the input/output data via the transmission function. The device 3 contains a memory 4. Then the supervisory time is changed according to the state of transmission. That is, the supervisory time is increased after the initial transmission of a long transmission interval and then decreased at the input/output transmission in a normal operation state of a short transmission interval respectively. Thus the device 3 can quickly detect the abnormality of the controller in a normal operation state.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a stored programming type programmable controller that is on a transmission path and has the sole initiative, and transfers money according to the programmable controller. The present invention relates to a control system equipped with an input/output device that performs input/output transmission between the input and output devices, and particularly to a monitoring method for monitoring the state of a programmable controller by having the input/output device monitor the transmission cycle.

[Conventional technology]

As shown in FIG. 6, a conventional control system includes, for example, a stored program type programmable controller 2 that has sole initiative over the transmission line 1 and has a built-in control program, and a programmable controller 2 that is connected to the transmission line 1. According to this, there is an input/output device 3 that performs input/output transmission and reception.

FIG. 7 is a diagram 70 for explaining the main processing of the programmable controller.

1) Perform initial processing inside the programmable controller (clearing memory, etc.) (see ■).

2) Turn off all flags that permit input/output transmission to the input/output device (see ■).

3) Enable interrupts (interrupts are prohibited at the rising edge) (see ■).

4) Perform initial transmission to all input/output devices on the transmission path. The programmable controller recognizes the presence or absence of an input/output device on the transmission path based on the response to this initial transmission (see ■).

5) When all initial transmissions are completed, execute the built-in control program according to the configuration of the input/output device (see ■)
.

6) Turn on the input/output transmission permission flag (this enables input/output transmission) (see ■).

FIG. 8 shows the reception interrupt processing of the programmable controller.

1) If you receive the initial transmission, register the input/output device, and once the initial transmission of all Ota blade devices is completed,
Turn on the initial transmission completion flag (■, ■, ■
, see ■).

2) When receiving an input/output transmission, store the input data of the input/output device (see ■, ■, ■).

3) Initial transmission If a transmission other than two-person output transmission is received, no processing is performed.

Note that the data to be transmitted includes information that distinguishes between initial transmission and input/output transmission (for example,
:H) is determined to be initial transmission, and 02[:H:] is determined to be human output transmission. ].

FIG. 9 shows the periodic interrupt processing of the programmable controller.

1] When the input/output transmission permission flag turns ON, output data is transmitted to the input/output device.

Through the processes shown in FIGS. 7, 8, and 9, the programmable controller performs input/output transmission to the input/output device at regular intervals while executing the control program after completing the initial process. What should be noted here is that after the initial transmission, the control program is executed during the transition to normal input/output transmission. The reason for this is that all input/output transmissions are performed after the data is established, which is common in this type of control device.

FIG. 10 is a flow diagram for explaining the main processing of the input/output device.

1) Perform initial processing inside the turnout device (see ■).

2) Enable interrupt processing (see ■).

3) Perform loop processing and wait until the initial transmission completion flag turns ON (see ■).

4) When the programmable controller abnormality flag is ON, it is determined that the programmable controller is abnormal, and the input/output device does not process input/output data (
■Reference).

5) Repeat the process of 4).

FIG. 11 is a diagram 70 for explaining reception interrupt processing of the input/output device.

1) If the data received from the transmission path is for initial transmission, return an initial transmission response and set the initial transmission completion flag to iON (■).

■Reference).

2) If the received data is input/output transmission, capture the output information (see ■).

3) Reply as a response to the manual transmission of data (see ■).

4) When either initial transmission or input/output transmission is received, turn on the reception completion flag (see ■).

FIG. 12 is a flow diagram for explaining the periodic interrupt processing of the input/output device.

1) When the reception completion flag is ONI, it is determined that the transmission is active, the timer is reset (cleared), and the reception completion flag is set to 1 OFF (see ■ and ■).

2) If the reception completion flag is OFF, it is determined that there is an abnormality in the transmission, and the timer is incremented (see ■).

3) Immediately after 2), when the timer value exceeds a predetermined value, it is determined that the time has elapsed, and the program controller abnormality flag is turned ON (see ■).

The above is the processing of the input/output device. Here, conventionally, the monitoring time is generally set to the maximum value of the transmission interval. In this case, the time interval between initial transmission and input/output transmission is the longest because the control program is executed.
Assuming that the maximum execution time of the control program is t-2.5 seconds,
The monitoring time should be set to about 5 seconds considering the margin. The input/output device can recognize the status of the programmable controller (normal or abnormal?) by monitoring the transmission time interval by the programmable controller, and in the case of an abnormality, the input/output device immediately stops input/output processing. becomes possible. Such input/output device processing is required to prevent the programmable controller osxrtc from adversely affecting the object to be controlled.

[1lffl to be solved by the invention] In the conventional system, the input/output device is the state f of the programmable controller.
: When recognizing by a low transmission interval, it is common to set the monitoring time to the maximum value of the transmission interval, and as a result,
Since monitoring is performed using this maximum setting time even when the transmission interval is short, a problem arises in that the recognition of abnormality by the programmable controller is delayed.

[Means to solve the problem]

In order to solve this problem, it is possible to save a file that saves the current transmission status (initial transmission, input/output transmission) in the memory of the input/output device, and the time to monitor the status of the programmable controller. A file is created and a function is added to change the monitoring time depending on the transmission status for the status monitoring process of the programmable controller.

[Effect]

The monitoring time is changed depending on the transmission state; that is, the monitoring time is lengthened after the initial transmission where the transmission interval is long, and the monitoring time is shortened during input/output transmission during normal operation where the transmission interval is short. This allows the input/output device to quickly recognize abnormalities in the programmable controller during normal operation.

[Tora completely defeated]

FIG. 1 is a block diagram for explaining the invention in detail. As shown in the figure, there is a stored program programmable controller 2 that has the sole initiative over the transmission line 1 and has a built-in control program, and a transmission function that is connected to the transmission line 1 and performs transmission according to the programmable controller 2. The input/output device [3 has a memory 4 inside it.

In such a configuration, a file as shown in FIG. 2 is created in the memory built into the input/output device.

b) The time monitoring counter is incremented and reset (cleared to zero) by periodic processing.
This is the counter (file) that is displayed. By looking at this file, the current elapsed time (time after reset)
(The unit of M is 10m5n.

口) The monitoring time file is a file that stores the time for time monitoring (basic unit is 10m5).

Using the above files, the input/output device processing is performed as follows.

FIG. 3 shows the main processing of the input/output device. Although there is almost no difference from that explained in the prior art, in the present invention, the 10th
After the initial processing inside the input/output device explained in the figure,
The difference is that the following processes ■ and ■ have been added.

■ Clearing the time monitoring counter to zero ■ Setting “13” in the monitoring time file (“13”
” is the normal monitoring time (130 mS).

FIG. 4 shows the reception interrupt processing fee of the input/output device. This is the process of FIG. 11 plus the following processes ① and ②.

■ When the initial transmission is received, "soo" is set in the monitoring time file (this makes the monitoring time 5 seconds).

■ If a transmission other than the initial transmission is received, 13'' is set in the monitoring time file (thereby, the monitoring time becomes 130 milliJ seconds).

FIG. 5 shows periodic interrupt processing of the input/output device.

This is the process of FIG. 12 with the following functions added. It is assumed that this periodic interrupt process is started every 10 m5.

1) If the reception completion flag is OFF, increment the time monitoring counter. Further, the time-over check is performed when the counter is compared with the monitoring time file set by the reception interrupt and it is determined that the counter is thicker (see ■ and ■).

2) If the reception completion flag is ON, clear the time monitoring counter to zero (see ■).

Mata, regarding the processing of programmable controllers,
It is exactly the same as FIGS. 7 to 9. In addition, the input/output transmission sent from the programmable controller is 1 in this case.
Assume that it is sent every 0 mS.

As a result of the processing described above, when monitoring the status of the progera/pull controller by the input/output device, the monitoring time from receiving all initial transmissions to receiving input/output transmissions is long (
5 seconds), -The monitoring time after receiving input/output transmission is short (
(130 ml, 1 second). In other words, by lengthening only the initial time monitoring that requires time and shortening it normally, the input/output device can quickly recognize abnormalities in the programmable controller.

〔Effect of the invention〕

According to this invention, it is possible to lengthen the monitoring time only for time monitoring after the initial transmission when there is a transmission interval, and shorten the monitoring time in normal cases, and it is possible to recognize the state of the programmable controller by the input/output device in normal situations. Since this can be done quickly, reliability is improved over the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining the invention in detail,
Figure 2 is an explanatory diagram for explaining the files provided in the input/output device, Figure 3 is a flow diagram for explaining the main processing of the input/output device shown in Figure 1, and Figure 4 is the same for the input/output device. FIG. 5 is a flowchart for explaining the periodic interrupt processing of the input/output device, and FIG. 6 is a block diagram showing an example of a conventional control system. , Figure 7 shows the program bar shown in @ Figure 6, 11
/A flowchart for explaining the main processing of the controller, Fig. S, Fig. 70, also for explaining the reception interrupt processing of the programmable controller, and Fig. 9, also for explaining the fixed periodic interrupt processing of the programmable controller. FIG. 10 is a 70-diagram for explaining the main processing of the input/output device shown in FIG. 6, and FIG. 11 is a flow diagram for explaining the reception interrupt processing of the input/output device. The twelfth factor is a flowchart for explaining the periodic interrupt processing t of the input/output device. Mark Jij Description 1...fi sending, 2...programmable controller, 3...input/output device, 4...memory. Agent Patent Attorney Akio Namiki Agent Patent Attorney Kiyoshi Matsuzaki @ 1 Figure 2 Figure (a) [2=============]
θ Line spacing (Cow crocodile for shellfish 0.) Mouth ========ko Viewing time 7゛9 @Figure 3? X5 Figure Shoulder 6 Figure $4 Figure Figure O8 Guo 9 Figure goo Figure H

Claims (1)

[Scope of Claims] A programmable controller that connects via a transmission path a programmable controller that performs control according to a built-in program and at least one input/output device that transmits and receives data based on commands from the programmable controller. performs initial transmission to the input/output device to check the presence or absence of the input/output device on the transmission path, and then performs input/output transmission to periodically transmit input/output data while running the program. A programmable controller characterized in that the input/output device has a long monitoring time from initial transmission to input/output transmission, and a short monitoring time after input/output transmission, in order to monitor the time interval of transmission by the programmable controller. monitoring method.