JPH04235603A - Pc signal trace control system - Google Patents

Abstract

PURPOSE:To correctly grasp the changing state of a desired signal by tracing the ON/OFF states of the signal in an optional timing. CONSTITUTION:A program executing means 3 carries out successively the ladder program stored in a program storage area 1. An instruction of an address (n+3) is identical with 8 trace instruction TRACE 5, and traces the ON/OFF states of the signal contained in the net of the front stage of the net including the TRACE 5. That is, a trace executing means 4 stores the ON/OFF states of signals A, B and C in the bit areas 2a, 2b and 2c of a trace signal storage area 2 respectively when the means 3 carries out the TRACE 5. Thus the ON/ OFF states of a desired signal is correctly grasped when a trace instruction is inputted right after the signal.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a PC signal trace control system, and particularly to a PC signal trace control system that performs tracing at arbitrary timing.
This invention relates to a signal trace control method of C.

0002

[Prior Art] When developing or maintaining a PC sequence program, in order to investigate the cause of a malfunction,
It is necessary to know the state of change in the signals of each part. Changes in these signals are displayed on a display device of the PC or a numerical control device connected to the PC. However, if the signal changes quickly or occurs infrequently, it may be difficult to confirm with the human eye. Therefore, a so-called trace control method is used in which the state of change of a desired signal is memorized at fixed time intervals and slowly reproduced on the screen of a display device.

0003

[Problems to be Solved by the Invention] However, in the conventional trace control method, the trace timing was performed at a fixed period, for example, every execution cycle of a sequence program, so as shown in FIG. Even if there was a temporary change to OFF within the circuit, the trace results would all be 1, making it impossible to detect the change. This is because signals often change during the execution of the program, whereas in the past, tracing was performed regardless of this. The present invention has been made in view of these points, and it is an object of the present invention to provide a signal trace control system for a PC that can accurately determine the state of change of a desired signal.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a signal trace control system for a PC (programmable controller) that traces the changing state of signals of a sequence program.
program storage means in which a program is stored; trace signal storage means in which the signal to be traced is stored;
program execution means for sequentially executing the sequence programs in the program storage means; and during execution of the sequence program by the program execution means, if the sequence program includes a trace instruction, the trace instruction and trace execution means for storing a signal included in a previous instruction in the trace signal storage means.

[0005]

[Operation] The program execution means sequentially executes the sequence programs in the program storage means. If the executed sequence program includes a trace instruction, the trace execution means stores the signal included in the instruction before the trace instruction in the trace signal storage means. Therefore, all desired signal change states are stored.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Figure 2 shows a numerical control device (
FIG. 2 is a block diagram of the entire hardware of the CNC. PM
A C (programmable machine controller) 20 is built into a numerical control device (CNC) 10. The processor 11 is a central processor for controlling the entire numerical control device (CNC) 10, and is connected to the ROM 1 via a bus 19.
The system program stored in 3 is read out, and according to this system program, the numerical control device (CNC) 1 is
Executes overall control of 0.

[0007] The shared RAM 12 is shared by the CNC 10 and the PMC 20.
This is a RAM for exchanging data with the shared RAM 12, and exchanging data with each other via this shared RAM 12. It also stores data necessary for access from both sides at the same time. The RAM 14 stores temporary calculation data, display data, etc. The CMOS 15 is configured as a nonvolatile memory, and stores tool correction amounts, pitch error correction amounts, machining programs, parameters, and the like. The CMOS 15 is backed up by a battery (not shown) and serves as a non-volatile memory even when the power of the numerical control unit (CNC) 10 is turned off, so its data is retained as is. The CMOS 15 also stores parameters necessary for the PMC 20 side.

The graphic control circuit 16 converts digital data such as the current position of each axis, alarms, parameters, image data, etc. into image signals and outputs the image signals. This image signal is sent to the display device 31 of the CRT/MDI unit 30,
It is displayed on the display device 31. Parameters, ladder diagrams, etc. on the PMC 20 side can also be displayed on the display device 31. At this time, the data is sent from the PMC20 to the shared RA.
It is sent via M12.

The interface 17 receives data from the keyboard 32 in the CRT/MDI unit 30 and passes it to the processor 11. Further, data to the PMC 20 side can also be input from the keyboard 32, and the data is sent to the PMC 20 side via the shared RAM 12.

The interface 18 is an interface for external equipment, and external equipment 40 such as a paper tape reader, paper tape puncher, paper tape reader/puncher, printer, etc. is connected thereto. A machining program is read from the paper tape reader, and the machining program edited in the numerical control device (CNC) 10 can be output to the paper tape puncher.

A PMC (programmable machine controller) 20 includes a processor 21 for the PMC, and the processor 21 is connected to a shared RAM 12 by a bus 25, and the shared RAM 12 is coupled to a bus 19 of the CNC 10. Further, a ROM 22 is coupled to the bus 25. A management program and a sequence program for controlling the PMC 20 are stored in the ROM 22 . In the embodiment of the present invention, the sequence program is created in ladder language. Also, instead of ROM22, ROM
In some cases, a cassette interface is provided, a sequence program is stored in a ROM cassette, and the sequence program is connected to the ROM cassette interface. By doing so, the sequence program can be easily upgraded or changed.

Further, a RAM 23 is coupled to the bus 25, and input/output signals are stored in the RAM 23, and the contents thereof are rewritten as the sequence program is executed. The I/O control circuit 24 is connected to the bus 25, converts the output signal stored in the RAM 23 into a serial signal, and sends the serial signal to the I/O unit 26. It also converts the serial input signal from the I/O unit 26 into a parallel signal and sends it to the bus 25. The signal is stored in RAM 23 by processor 21.

[0013] The processor 21 receives a shared RA from the CNC 10.
Receive command signals such as M function command and T function command via M12, temporarily store them in RAM23, and then transfer the commands to ROM.
The I/O unit 2 is processed according to the sequence program stored in the I/O unit 22 and
Output to 6. This output signal controls hydraulic equipment, pneumatic equipment, and electromagnetic equipment on the machine side.

The processor 21 also has an I/O unit 2.
Input signals such as a limit switch signal on the machine side and a signal from an operation switch on a machine operation panel are received from 6, and the input signals are temporarily stored in the RAM 23. Input signals that do not need to be processed by the PMC 20 are sent to the processor 11 via the shared RAM 12. Other signals are processed by the sequence program, some signals are sent to the CNC side, and other signals are sent to the I/O control circuit 24 as output signals.
It is output from the O unit 26 to the machine side.

On the other hand, the sequence program can include instructions for controlling the movement of each axis. When these commands are read by the processor 21, they are sent to the processor 11 via the shared RAM 12 to control the servo motor. Similarly, a spindle motor etc. can also be controlled by commands from the PMC side. ROM
Sequence program stored in 22, RAM 23
The input/output signals stored in the CRT/MDI unit 30
can be displayed on the display device 31 of. Further, signals traced during execution of the sequence program are also displayed on the display device 31.

FIG. 3 is a ladder diagram showing a specific command method of the signal trace control method of the present invention. Now, for example, if you want to trace the on/off states of each signal A, B, and C of net 5, use the trace command TRAC to the net 6 after it.
Insert E5. The CPU 21 of the PMC 20 reads the trace command TRACE5 and at the same time traces the on/off states of the signals A, B, and C at that time into the RAM 23.

FIG. 1 is a conceptual diagram specifically showing the procedure of the signal trace control method by the CPU 21. In the figure, 1
is a program storage area secured within the RAM 23, in which the ladder program is stored. 2 is a trace signal storage area for storing signals to be traced in this ladder program.

The program execution means 3 sequentially executes the programs in the program storage area 1. Then, trace instruction 1d at address n+3, that is, TRA
Run CE5. At the same time, the trace execution means 4 executes each address n, n+1 specified by the trace instruction 1d.
, n+2 of the instructions 1a, 1b, 1c, that is, the on/off states of the signals A, B, C of the net 5 in FIG. 2b and 2c.

In this way, the trace execution means 4 successively stores the signals of the nets preceding the net of the trace command in the trace signal storage area 2. Then, by displaying the contents of this trace signal storage area 2 on the display device 31 later, it is possible to check the change state of the signal. Note that the trace specification is not limited to each net, and may be only a signal included in an instruction preceding a trace instruction, that is, signal C in FIG. 3. For this purpose, it is necessary to be able to specify a signal in the trace command.

In this way, tracing can be performed at any timing by issuing the trace command immediately after the command containing the signal to be traced. That is,
Normally, by performing tracing immediately after execution of an instruction in which the on/off state of a signal tends to change, changes in the signal can be accurately captured, as shown in the time chart of FIG.

[0021]

As explained above, in the present invention, if the sequence program executed by the program execution means includes a trace instruction, the trace execution means converts the signal included in the instruction before the trace instruction into a trace signal. Store in storage means. Therefore, since tracing can be performed at any timing, it is possible to accurately capture the change state of a desired signal.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a signal trace control method of the present invention.

[Fig. 2] Numerical control device (CNC) for implementing the present invention
) is a block diagram of the entire hardware.

FIG. 3 is a display example of a ladder diagram on a display screen.

FIG. 4 is a time chart of the signal trace control method of the present invention.

FIG. 5 is a time chart of a conventional signal trace control method.

[Explanation of symbols]

1 Program storage area 2 Trace signal storage area 3 Program execution means 4 Trace execution means

Claims (2)

[Claims] 1. A signal trace control system for a PC (programmable controller) that traces change states of signals of a sequence program, comprising a program storage means in which the sequence program is stored and a signal to be traced. a trace signal storage means, a program execution means for sequentially executing the sequence program in the program storage means, and during execution of the sequence program by the program execution means;
If the sequence program includes a trace instruction, the PC further comprises trace execution means for storing a signal included in an instruction preceding the trace instruction in the trace signal storage means. Signal trace control method. 2. The sequence program is a ladder program, and during execution of the ladder program by the program execution means, if the ladder program includes a trace instruction, the trace execution means 2. The signal trace control method for a PC according to claim 1, wherein a signal included in a command of a net preceding the trace command is stored in the trace signal storage means.