JPS63126007A - Programmable controller - Google Patents

Abstract

PURPOSE:To allow a user program to set up cycle time monitoring time optionally by forming a cycle time monitoring time setting instruction. CONSTITUTION:A programmable controller is provided with a CPU 1, an alarm buzzer 1a, an alarm display device 1b, a system memory 2, a user memory 3, an I/O memory 4, an I/O unit 5, a work memory 6, a cycle time measuring timer module 7, and a programming console 8. When the system is raised by turning on a power supply, a previously fixedly set-up default value is registered as the cycle time monitoring time. When a program is run by the console 8 that an instruction read out from the memory 3 is decided as a cycle time monitoring time setting instruction, the monitoring time specified by an operand is registered. Consequently, the cycle time monitoring time can be optionally set up in accordance with the transition of a control process and the feature of a controlled system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to improvements in scanning-type programmable controllers.

(Summary of the Invention) In the present invention, instructions are sequentially read out from a user program according to the value of a program counter, decoded to determine that the read instruction is a cycle time monitoring time setting instruction, and then read out instruction words that are read out as a cycle time monitoring time setting instruction. is decoded, the cycle time monitoring time is reset according to the time specified directly or indirectly by the operand of the instruction word.This allows the cycle time monitoring time to be changed via the user program. It can be set arbitrarily.

(Prior Art and its Problems) Conventionally, in scanning type programmable controllers, a watchdog timer or a normal timer module is used to monitor cycle time exceedance. Here, the cycle time is, for example, in the case of the END refresh method, the time required to execute one cycle of user program execution, I10 refresh, and peripheral device service in RUN mode.

However, in such conventional programmable controllers, operations related to setting or changing the cycle time monitoring time are not open to the user. However, there were problems such as cycle time monitoring times were not always appropriate.

(Purpose of the invention) The purpose of this invention is to improve the scale of user programs.

Our objective is to provide a programmable controller that allows the cycle time monitoring time to be freely set according to the transition of the control process, the characteristics of the controlled object, etc.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention includes an instruction reading means for sequentially reading out instructions from a user program according to the value of a program counter, and an instruction reading means for sequentially reading out instructions from a user program according to the value of a program counter, and A command decoding means decodes that it is a setting command, and when the cycle time monitoring time setting command is decoded, the cycle time monitoring time is set according to the time specified directly or indirectly by the operand of the command. The present invention is characterized by comprising a monitoring time setting means for adjusting the monitoring time.

Such a configuration has the advantage that the cycle time monitoring time can be freely set in the user program in accordance with the scale of the user program, the transition of the control process, the characteristics of the controlled object, etc.

(Description of Embodiments) FIG. 1 is a block diagram showing the electrical hardware configuration of a programmable controller according to the present invention.

As shown in the figure, this programmable controller has CPU1. Alarm buzzer 1a, alarm indicator 1b,
System memory 2. User memory 3, I10 memory 4.
110 units5. It is equipped with a work memory 6, a timer module 7 for cycle time measurement, and a programming console 8.

The CPUI is mainly composed of a microprocessor, and is configured to realize various functions of the programmable controller by executing a system program stored in the system memory 2.

The basics of these functions are to write the input data read from the I10 unit 5 to the input canister of the I10 memory 4, and to send the contents of the output canister of the I10 memory 4 to the outside via the I10 unit 5. The I10 refresh function reads the user command words 1 iiN from the user memory 3 according to the program counter, decodes them, reads the corresponding input or output from the I10 memory 4 according to the decoding result, and executes the specified logic. A user program execution function that performs calculations and rewrites the output data of the I10 memory 4 with the calculation results, and detects key operations on the programming console 8,
It consists of peripheral device service functions that perform program writing, reading, and monitoring.

When the operation mode is in the RUN mode, the user program execution process, the I10 refresh process, and the peripheral device service process are sequentially and cyclically executed.

In this embodiment, the cycle time is defined as the time required to execute one round of the user program execution process, the I10 refresh process, and the peripheral device service process. Further, the work memory 6 is used for storing intermediate calculation results during each of the above processes.

The alarm buzzer 1a and the alarm display 1b are activated when the cycle time exceeds the monitoring time, as will be described later.

Next, FIG. 2 is a general flowchart schematically showing a system program executed by the CPU 1. As shown in FIG.

In the figure, when a program is started by power-on, etc., a conventionally known power-on initial process is performed, and various registers, counters, etc. are initialized (step 201).

Next, the cycle time monitoring time is registered as a default value (standard value) fixedly set in advance (step 20
2). Note that this registration to the default value has been conventionally performed.

Next, run RUN on programming console 8.
Until a key operation corresponding to the mode is performed (No in step 203), the above-mentioned I10 refresh process (
Step 204) and peripheral device service processing (step 205) are repeated.

In response, the key operations of the programming console 8 are read in the peripheral device service (step 205),
When the RUN mode is confirmed (Yes at step 203), a predetermined activation command is given to the cycle time measurement timer module 7, and the cycle time monitoring timer is activated (step 206).

Thereafter, as described above, the user program execution process (step 207) and the I10 refresh (step 208)
and peripheral device service processing (step 209) are performed sequentially, and the cycle time is measured during this time. In particular, in the present invention, in the user program execution processing (step 207), the special processing shown in FIG. By executing such processing, the cycle time monitoring time can be reset by the user program.

That is, when the user program execution process is started in FIG. Step 2072), it is determined whether the read instruction is a cycle time monitoring time setting instruction (Step 2073>).

Here, as shown in FIG. 4, the structure of the cycle time monitoring time setting command is composed of an operation code 5YCL and an operand #0050.

If it is not a monitoring time setting command (No in step 2073), it is confirmed that it is not an END command (step 20
76 (No) and executes the corresponding command (Step 207
7>, the value of the program counter PC is updated by +1 (step 2078>, the above instruction reading and decoding is repeated).

On the other hand, if the operation code corresponding to the cycle time monitoring time setting command is confirmed (step 2071) and the input 1001'fiONL is connected in series with this (see Figure 4), then the operation at that point is The power flow register PF storing the result becomes 111 IT (contaminated in step 2074), and the value of the operand #O○50 is immediately registered in the work area as a monitoring time of 50 m5 (step 2075A).

That is, by writing #0050 in the operand of the cycle time monitoring time setting command, the value of the cycle time monitoring time can be registered as 5QmS.

Then, the read instruction (step 2072)
If it is determined to be a D command (step 2076), the user program execution process ends, and the process returns to the flow shown in FIG. 2 to perform the I10 refresh process (step 208).
After the peripheral device service processing (step 209) is sequentially executed, the cycle time is checked (step 210).

Here, the cycle time value read from the cycle time measurement timer module is determined at step 20 in FIG.
If it is shorter than the monitoring time registered in the work area in step 75A (No in step 210), user program execution processing (step 207>).

It is assumed that both the I10 refresh process (step 208) and the peripheral device service process (step 209) have been performed normally, and the above operations are repeated.

On the other hand, if it is determined in step 210 that the cycle time is greater than the monitoring time (
step 2101), user program execution processing (step 207), I10 refresh processing (step 2
08) and peripheral device service processing (step 209) are determined to be abnormal, a cycle time over warning is output, the alarm buzzer 1a sounds, and at the same time a cycle time over warning display is performed (step 2).
12>, the alarm indicator 1b lights up.

Therefore, the user uses the alarm buzzer 1a and the alarm display 1b to perform the user program execution process (step 207>
, I10 refresh processing (step 208), or peripheral device service processing (step 209) can confirm that an abnormality has occurred, and necessary processing can be performed immediately.

In this embodiment, whether or not the cycle time exceeds the monitoring time is determined by software by reading the measured value of the timer module (step 210). Of course, the CPU 1 may be forcibly reset by output.

Next, FIG. 5 shows another embodiment of the present invention. In this example, as shown in FIG.
As shown in FIG. 5, it is determined that the read instruction word is a cycle time monitoring time setting instruction (determined at step 20734), and furthermore, it is determined that the power flow register PF="1". (Step 207
4), data memory (in this example, I10 memory 4
The contents of the specified channel (CHlo) of
075B).

According to this example, even if the monitoring time has a large number of digits, there is no need to write it into the user program, so it is possible to finely adjust the cycle time monitoring time using a high-speed clock timer. Become.

Furthermore, FIG. 7 shows still another embodiment of the present invention,
In this example, as shown in FIG.
0010, and on the other hand, when the instruction read in FIG. 7 is confirmed to be a cycle time monitoring time setting instruction (step 2073 affirmative), and the value of the power flow register PF is determined to be 1'' (step 2074 affirmative). , a specified time value (±10 m5) is added to the current monitoring time every scan, and this is registered as a new cycle time monitoring time.

According to this example, as long as the input 102 is in the ON state, the cycle time monitoring time can be increased or decreased in steps, and the cycle time monitoring time can be used to feedback control the cycle time monitoring time. can.

As is clear from the description of each embodiment above, according to the present invention, the cycle time monitoring time can be arbitrarily set and changed via the user program.
Users can freely programmably set the desired cycle time monitoring time according to the purpose of the PC or by user instructions for each process, and high-speed scanning is required with little margin for the scanning performance of the PC being used. Even in processes where monitoring is performed, the reliability of the system can be improved because retry processing and abnormal processing when the monitoring time exceeds can be programmed using the alarm output.

In addition, in this invention, the cycle time monitoring time setting command is used as a power flow register P in the same way as a normal OUT command.
Since the program can be executed subject to the contents of F as a condition, the degree of freedom of the program can be increased by taking various conditions as inputs connected in series to this.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical hardware configuration of a programmable controller according to the present invention, FIG. 2 is a general flowchart showing the software configuration, and FIG. 3 is a detail flowchart showing details of user program execution processing. , FIG. 4 is a ladder diagram showing an example of the cycle time monitoring time setting command, FIG. 5 is a detailed flowchart showing another example of the user program execution process, and FIG. 6 is another example of the cycle time monitoring time setting command. FIG. 7 is a detailed flowchart showing yet another example of user program execution processing; FIG.
The figure is a ladder diagram showing yet another example of the cycle time monitoring time setting command. 1... CPU 1a... Alarm buzzer 1b... Alarm display 2... System memory 3... User memory 4... I10 memory 5 ......I10 unit 6...Work memory 7...Timer module for cycle time measurement 8...Programming console Figure 1 IaC sound report () No. Figure 2 Figure 4 Figure 6 Figure 8

Claims (1)

[Claims] (1) Instruction reading means for sequentially reading instruction words from a user program according to the value of a program counter; instruction decoding means for decoding that the read instruction words are cycle time monitoring time setting instructions; The present invention further comprises monitoring time setting means for resetting the cycle time monitoring time according to the time specified directly or indirectly by an operand of the command when the time monitoring time setting command is decoded. Features a programmable controller.