JPH0443402A - Monitoring method for programmable controller - Google Patents

Abstract

PURPOSE:To obtain highly precise monitor information by collecting monitor information as to the object of control, which corresponds to address information, in synchronizing with the scan of the object of control by means of a programmable controller. CONSTITUTION:Address information which is set in a monitor device 1 is transmitted to the programmable controller 3 and then it collects monitor information in synchronizing with the scan of the object of control. When a monitor command transmitted from the monitor device 1 is received in the programmable controller, collected monitor information is transmitted to the monitor device 1. Thus, a deviation between time required for collection and scan time is prevented and highly precise monitor information can always be obtained by collecting monitor information in synchronizing with the scan of the object of control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a programmable controller monitoring method for checking the operating state of the programmable controller.

[Conventional technology]

When automating equipment, programmable controllers equipped with computing means such as computers are often used, and these programmable controllers control installed equipment according to written ladder programs. In addition, programmable controllers are capable of efficiently debugging program errors, adjusting timing, and maintaining equipment, as the number of objects to be controlled, such as internal relays and input/output terminals, tends to increase as equipment becomes larger and more distributed. In doing so, it is desired to be able to monitor the operating status of a specific controlled object.

A monitor device connected to the programmable controller via a communication cable is generally used to monitor the above-mentioned controlled object (see Figure 3), and the conventional monitoring method using this monitor device is As shown in the device side monitor routine in the figure, the address of the required monitor information is extracted as address information (521),
A command with the extracted address information is sent to the programmable controller (S22
). Then, after receiving the monitor information corresponding to the address information specified by the above command from the programmable controller and executing the information confirmation process, the monitor information is displayed (S23). If you want to change the contents of the controlled object, select YES in S2.
1, but if you do not want to change it, press S as No.
22 (S 24 ).

In this manner, in the conventional monitoring method, commands having address information are sequentially transmitted to the programmable controller, thereby obtaining monitor information corresponding to the transmitted address information. Therefore, by using this monitoring method, you can perform tasks such as debugging program errors, adjusting the timing of controlled objects, and maintaining equipment while monitoring the operation of a specific controlled object, thereby preventing runaway equipment, etc. It has become possible to prevent this from occurring and to implement it safely and quickly.

[Problem to be solved by the invention]

However, in the conventional monitoring method described above, each time monitor information is obtained from a programmable controller,
All the addresses of the required monitor information must be sent to the programmable controller together with the command, and the transmission of this command is a factor that reduces the accuracy of the monitor information.

In other words, the rate of error occurrence when transmitting and receiving signals is proportional to the amount of signals sent back and forth between the communication device and the programmable controller 9, and this amount of signals is proportional to the number of commands sent from the communication device. are doing. At this time, the number of commands mentioned above is proportional to the number of monitoring points, which is the number of monitor information, and the number of discrete addresses of monitor information. For example, when monitoring a large number of monitor information of discrete addresses, As the number of commands increases, the error rate increases.

Furthermore, the collection of monitor information in the programmable controller is performed asynchronously with respect to the operation of the programmable controller to scan each control target. Therefore, if the time required from sending a command to collecting monitor information increases, the collection of monitor information may be performed outside the scan time of one cycle, resulting in incorrect monitoring. There is a risk that information may be collected.

As described above, the conventional monitoring method is capable of monitoring the operation of a specific controlled object, but there is a problem in that the accuracy of the monitoring information decreases depending on the conditions of supervision. Therefore, in the present invention, by collecting monitor information in synchronization with the operation of the programmable controller to scan each controlled object, it is possible to always obtain highly accurate monitor information even when the monitoring conditions change. The purpose of this research is to provide a method for monitoring programmable controllers.

[Means to solve the problem]

In order to solve the above-mentioned problem, a monitoring method for a programmable controller according to the present invention collects 0NOFF information, which is monitor information about a controlled object corresponding to address information, in a programmable controller, and transmits the collected monitor information to a monitor device. In the programmable controller monitoring method that is transmitted and displayed, after the address information having, for example, 8 failed addresses set in the monitor device is transmitted to the programmable controller, the programmable controller transmits the address information in synchronization with the scan of the controlled object. The system is characterized in that when the monitor information is collected and the programmable controller receives a monitor command sent from the monitor device, the collected monitor information is sent to the monitor device and displayed.

[Function] According to the above configuration, the address information set by the monitor device is input in advance to the programmable controller. Furthermore, monitor information regarding the controlled object corresponding to the address information is collected in synchronization with the programmable controller scanning the controlled object. Therefore, by preventing a discrepancy between the time required to collect monitor information and the scan time, it is possible to prevent address information from changing depending on the control target to be monitored.
will be collected accurately no matter what.

In addition, when displaying monitor information on a monitor device,
The monitor command is sent from the monitor device, and the monitor information collected by the programmable controller is sent to the monitor device. Since the address information is sent in advance, there is no change in the number of commands.

Therefore, the amount of signals transmitted and received between the monitor device and the programmable controller is always the minimum necessary amount, and as a result, it is possible to minimize the error occurrence rate during communication. Reduction of the error occurrence rate during communication and prevention of the above-mentioned deviation between the collection time and the scan time make it possible to always obtain highly accurate monitor information.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The programmable controller monitoring method according to this embodiment is executed by connecting the monitor device 1 to the programmable controller 3 via the communication line 2, as shown in FIG. The above-mentioned monitor device 1 is equipped with a display section made of, for example, a liquid crystal panel, and the display section displays address information of controlled objects such as internal relays and input/output' terminals of a programmable controller, and 0N
- Monitor information such as OFF status is displayed. In addition, the monitor device 1 is equipped with a keypad that has a numeric keypad for specifying the address of a controlled object and special keys for instructing various processes such as break processing that temporarily interrupts execution, and displays the above-mentioned display. The operating state of a specific controlled object can be accurately grasped by the control section.

Furthermore, the monitor equipment is equipped with a C P connected to the above-mentioned display section and key power section via an interface section.
U (Central Processing 1J
nit). This CPtJ is a ROM (R
ead 0nly Mem.

The system recognizes key personnel and displays information on the display according to the system program stored in the RAM (Rand ry).
om Access Memory). The ROM also stores a device-side monitor program that executes a device-side monitor routine, and this device-side monitor program sends the address of a specific control target as address information to the programmable controller in advance, and then Monitor information corresponding to address information is obtained from the programmable controller using a collection command, which is a monitor command.

The programmable controller 3 to which the above address information and monitor commands are sent has a RAM in which a program area for storing ladder programs is formed.
An address area for storing address information transmitted from 1 and a monitor area for storing monitor information are also formed.

Furthermore, the programmable controller 3 has a ROM that stores a system program for analyzing the above-mentioned ladder program and a PC-side monitor program for executing a PC-side monitor routine, and the PC-side monitor program is specified by address information. The monitor information of the controlled object is stored in the monitor area, and this monitor information is transmitted to the monitor device 1 when a monitor command is received.

The ROM and RAM described above are connected to the CPtJ, and the CPU is also connected to input/output terminals for transmitting and receiving control signals via an interface section. As a result, the CPtJ monitors sensors installed in equipment and controls actuators and the like in accordance with the system program that analyzes the ladder program.

In the above configuration, the device side monitor routine and the PC
The operation order of the monitor device 1 and programmable controller 3 according to the side monitor routine will be explained below based on the flowcharts of FIGS. 1 and 2.

First, as shown in FIG.
It is connected to the programmable controller 3 via.

Thereafter, in the monitor W1, as shown in FIG. 1, a controlled object whose monitor information is to be displayed on the display section is specified, and an address of the controlled object is input from the key input section. The input address is temporarily stored in the RAM of the monitor device W1, and is used as address information that is a collection of all addresses in this RAM. This address information also includes discrete information, which is a set of discrete addresses, such as the address at address 1 and the address at address 5 (S
l).

When the input of the required address is completed, the above address information is sent from the monitor device 1 to the programmable controller 3 via the communication line 2 (S2), and following this address information, a collection command that is a monitor command is sent. (S3).

On the other hand, as shown in FIG. 2, the programmable controller 3 receives address information from the monitor device 1 and stores this address information in an address area formed in the RAM (Sll). The above address information is read from the address area every time the programmable controller 3 scans the controlled object, and the 0N-OFF state of the controlled object corresponding to the address information is stored as monitor information in the monitor area formed in the RAM. The stored information becomes - (S12).

Programmable controller that sequentially stores monitor information
The controller 3 monitors the presence or absence of a collection command sent from the monitor device 1, and if it does not receive a collection command, it returns NO and executes S12 again, while if it receives a collection command, If the answer is YES, S14 will be executed (S13). Then, when S14 is executed, the monitor information stored in the monitor area is sent to the monitor device W1, and then S12 is executed again (
S14).

The above monitor information is received by the monitor device W1, and as shown in FIG. 1, information confirmation processing is performed to determine whether the monitor information is a regular signal. If it is determined that the signal is a regular signal, monitor information will be displayed on the display section (S-4).

After this, it is determined whether an instruction to change the content has been input from the key personnel department, and if there is no instruction to change the content, No.
Then, the process is executed again from S3, and monitor information regarding the same address information is obtained from the programmable controller 3 and displayed. On the other hand, if there is an instruction to change the contents, Sl will be executed as YES, and the address that is the contents of the address information will be changed, so that the monitor' information of the controlled object that has been changed from the subsequent operation. will be displayed (S5).

In this way, the monitoring method of this embodiment stores address information in the programmable controller 3 in advance,
Thereafter, monitor information can be obtained from the programmable controller 3 by simply transmitting a monitor command to the programmable controller 3. At this time, the collection command is one command even in the case of discrete addresses or address information with a large number of monitoring points.

Therefore, the monitor device 1 and the programmable controller 3
Since the number of commands does not change, the amount of signals transmitted and received between the two terminals is always the minimum necessary amount, and as a result, it is possible to minimize the error rate during communication.

In addition, the collection of monitor information in the programmable controller 3 is possible because the address information is stored in advance.
This is done together with the scan of the controlled object.

As a result, the monitor information is collected in synchronization with the operation of scanning the controlled object, thereby preventing a discrepancy between the time required for collection and the scan time. Preventing this deviation, together with the above-mentioned minimum necessary monitor commands, makes it possible to always obtain highly accurate monitor information even when conditions change depending on the controlled object to be monitored.

Furthermore, in the monitoring method of this embodiment, since the address information is set separately from the monitor command, there is no need to change the monitor command when changing the address information, and there is no need to change the monitor command when changing the address information. This allows for efficient program changes.

〔Effect of the invention〕

As described above, the programmable controller monitor device according to the present invention collects monitor information in synchronization with the scan of the controlled object by the programmable controller after the address information set in the monitor device is transmitted to the programmable controller. The configuration is such that when the programmable controller receives a monitor command sent from the monitor device, the collected monitor information is sent to the monitor device.

As a result, the monitor information is collected in synchronization with the scan of the controlled object, thereby preventing a discrepancy between the time required for collection and the scan time. In addition, since the number of monitor commands does not change with respect to address information, it is possible to always keep the amount of signals sent and received between the monitor device and the programmable controller to the minimum necessary, which reduces the error rate during communication. can be minimized. Further, by reducing the error occurrence rate during communication and preventing the above-mentioned deviation between the collection time and the scan time, highly accurate monitor information can be obtained at all times.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention. FIG. 1 is a flowchart of the device side monitor routine. FIG. 2 is a flowchart of the PC side monitor routine. FIG. 3 is a schematic configuration diagram of a programmable controller and a monitor device connected via a communication line. FIG. 4 shows a conventional example and is a flowchart of a device-side monitor routine. 2 is a monitor device, 2 is a communication line, and 3 is a programmable controller. Patent applicant Sharp Co., Ltd.

Claims (1)

[Scope of Claims] 1. A method for monitoring a programmable controller in which monitor information about a controlled object corresponding to address information is collected by a programmable controller, and the collected monitor information is transmitted to a monitor device and displayed, comprising: After the address information set on the device is sent to the programmable controller, the programmable controller collects monitor information in synchronization with the scan of the controlled object, and when the programmable controller receives the monitor command sent from the monitor device. A method for monitoring a programmable controller, characterized in that collected monitor information is transmitted to a monitor device.