JPH0323921B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a step-by-step programmable controller that automatically controls machine tools and the like.

Generally, among programmable controllers, there is a step-by-step programmable controller that performs the operation of only one step among many steps and does not proceed to the next step unless the conditions in that step are satisfied. . Even when controlling a controlled device automatically using this type of step-by-step programmable controller, there are cases where it is necessary to operate each load individually or through motion, which is different from the automatic control. Since the step-by-step program aims at sequential control, it is not possible to perform multiple processes due to the large number of input states. Conventionally, this has been dealt with by providing a wire logic with contacts or non-contacts in addition to the step-by-step programmable controller. However, this requires separate wire logic, so
This is undesirable because it impairs the original features of the programmable controller, which aim to provide flexibility in control content and reduce manufacturing man-hours.

An object of the present invention is to provide a step-by-step programmable controller that eliminates the drawbacks of the conventional step-by-step programmable controller and enables not only sequential control but also multiple processes depending on the state of a large number of inputs. It is in.

In order to achieve the above object, the step-by-step programmable controller of the present invention has at least a first program area for automatic operation based on a step-by-step program in a user program storage section, and a first program area for manual operation based on a ladder representation. 2 program areas, and the program console section is provided with an automatic/manual operation switching means, and when the automatic operation is specified by the operation switching means, the central processing unit stores the information in the first program area. Read and execute the program for automatic operation,
When manual operation is specified, a manual operation program stored in the second program area is read and executed.

The present invention will be explained in detail below with reference to embodiments shown in the drawings.

FIG. 1 is a block diagram of a programmable controller in which the present invention is implemented. In the figure 1
is a CPU (central processing unit) that carries out processing operations of the system according to a system program stored in the system program storage ROM2. The system program ROM 2 stores an interpreter program for decoding and executing user programs and a program for controlling keyboard LEDs and the like. Reference numeral 3 denotes a user program RAM that stores programs created by the user using user command words such as AND, OR, and out. As shown in FIG. 7, this user program RAM has a step-by-step program storage area m1, a ladder representation program storage area m2 for manual operation, and another general ladder representation program storage area m3. . 4 is an I/O refresh memory that once receives and stores the status of the input/output device, which will be described later; 5 is a work area RAM used for temporary storage of flag status and data; 6 is the connection between the input/output device and the CPU 1. This is the input/output control section. Reference numeral 7 denotes a program console section used when creating a user program, which includes keys such as command key 7a, number key 7b, command key 7c, input/output display LED 7d, command word display LED 7e, error display 7f, address and A numeric display 7g for displaying data, an automatic/manual changeover switch 7h, etc. are provided on the panel surface 7i. 8 is CPU1, system program ROM2, user program RAM3,
This is a bus line that connects the I/O refresh memory RAM 4, the work area RAM 5, the input/output control section 6, and the program console section 7. 9 is an input interface for exchanging signals with external input; 10 is an output interface for exchanging output signals with external devices; 11 is an I/O for connecting the input/output control section 6, input interface 9, and output interface 10. It's a bus line. Further, 12 is a terminal block for receiving signals from external inputs, such as various switches, and 13 is a terminal block for connecting to external equipment.

FIG. 2 shows a suitable example of the case where the step-by-step programmable controller shown in FIG. 1 is used for control by a step-by-step program.
The figure shows a process in which a user transports an object to be plated from a predetermined location using a trolley 21, places it in a plating tank 22, soaks it for a certain period of time, and then returns it to its original location. In this case, the control is as follows:
The forward movement continues until the forward limit is detected by a limit switch or the like. When the forward limit is detected, the forward movement by the trolley 21 is stopped,
A descending operation is started to immerse the object to be plated into the plating tank 22. This lowering operation continues until the lowering limit is detected, and when the lowering limit is detected, the lowering operation is stopped. Then, the object to be plated is immersed in the plating tank 22 for a certain period of time, for example, 10 minutes. After 10 minutes have elapsed, the machine begins to move upward in order to pull up the object to be plated.
The rising operation continues until the rising limit is detected.
When the upper limit of the rise is detected, the object to be plated starts moving backward by the cart 21. Then, the backward movement continues until the backward limit is detected, and stops when the backward limit is detected, and the operation ends.

In order to automatically control the above steps, it is possible to create a program with ladder expression using contacts and shift registers as shown in FIG. However, in this case, in order to operate such a ladder representation program, the shift register 31
The clock input to the circuit must program the conditions for advancing to the next step in each process, and the data input must be programmed so that the output of the shift register 31 is only one point, so it is difficult to configure the circuit. It is difficult to create a program because the input circuit must be considered first, and then the output must be considered, making it completely impractical. Therefore, it is desirable to use the step-by-step program system for process control in the case shown in FIG. 2, as described above.

FIG. 4 shows a step-by-step program that advances the process control shown in FIG.

In Figure 4, in the first step 001, the instruction is "AND", the data (input) is "start", and the output is programmed as "none", and the condition is not satisfied until the start switch is turned on and "start" is executed. It doesn't work, so I'm stuck at this step. When "start" is input, the process advances to the next step 002. In this step 002, the instruction is "AND"
Then, the output is programmed as "forward" with the data "advance limit", and as expected, unless the "advance limit" input is entered, the condition is not met and the step remains at this step and the "forward" output continues. When the input ``advance limit'' is entered, the condition is met and the process moves to the next step 003. Similarly, if the input condition is not satisfied in steps 003 to 006, the process remains at that step, but if the condition is satisfied, the process advances to the next step. Then, when the "backward limit" is input in step 006, the condition is satisfied in step 006, and the next step 006 is started.
A termination command is issued. The operation flow of the step-by-step program system shown in Fig. 4 is as follows.
The result will be as shown in the figure. That is, in operation step 51, the instruction of the current step stored in work area RAM 5 is read out, in step 52 the instruction is decoded, and in step 53, conditions are determined based on the instruction and data. In step 54, it is determined whether the condition is satisfied. If the condition is not met, the output is stored in the I/O refresh memory 4 in step 56, and
Return to step 51. If the condition is met at step 54, the current step of the program is incremented by 1 at step 55, that is, the program advances by one step, and at operation step 56, the output is stored in the I/O refresh memory 4.
Store it and return to step 51.

The step-by-step program shown in FIGS. 4 and 5 is created by the user in order to cause the controlled object to perform a certain fixed operation.
As mentioned above, this is convenient for automatically controlling the series of steps shown in the figure. However, since steps other than the step currently being executed do not proceed even if conditions are met in other steps, it is not possible to obtain outputs corresponding to each condition being met.

Therefore, in this embodiment, as shown in FIG. 6, in addition to the step-by-step program shown in FIG. Programs are also prepared. FIG. 6A is a step-by-step program for automatic operation, and FIG. 6B is a ladder representation program for manual operation. Since FIG. 6A is similar to that shown in FIG. 4, a description thereof will be omitted.
FIG. 6B is a program that allows the outputs ``forward'', ``descend'', ``ascend'', and ``reverse'' in FIG. 6A to be individually and independently controlled manually. For example, a "forward" output is obtained with the input conditions of "forward PB (button switch) on" and "no advance limit", and a "rise" output is obtained with the input conditions of "upward PB on" and "no upward limit". That's what I do. The step-by-step program for automatic operation shown in FIG. 6 and the ladder representation program for manual operation are created and stored in storage areas m1 and m2 of the user program RAM 3, respectively, as shown in FIG. When the automatic/manual changeover switch 7h in the console section 7 is set to "auto", reading is started from the head address a of the step-by-step program shown in FIG. 7, and the operation of the step-by-step program is executed. However, when the "STEP END" command stored at the final address b of the step-by-step program storage area m1 is read, the manual operation program area m2 is skipped and the command indicating the end of the manual circuit is stored at address d. The execution of the general ladder representation program stored from the next address e begins. If automatic/manual switch 7h is set to "manual", address b where the "STEP END" command of the step-by-step program is stored.
Addresses the next address c, creates or executes a ladder expression program for manual operation, and then enters a general ladder program.

FIG. 8 shows a control flow of the programmable controller shown in FIG. 1, which includes the program storage areas shown in FIGS. 6 and 7.

In FIG. 8, at step 80, a determination is first made as to whether the process is automatic or manual. Automatic/manual switch 7
is set to ``Auto'', the step
At step 81, the program step currently being executed stored in the work area RAM 5 is read, and at step 82, the instruction is analyzed and conditions are determined. Then, in step 83, it is determined whether the condition is satisfied or not.
If the condition is not satisfied, the program step is left as it is at step 85, the output is stored in the I/O refresh memory 4, and the process moves to step 86. If the condition is met in step 83, step 84
Then, add 1 to the step number of the program and move to operation step 86. At step 86, the execution PC (program counter) is set to the next address after manual termination (FIG. 7e). After that, the operations of reading, analyzing, and executing a program in general ladder representation proceed. That is, in step 87 the execution PC is read and analyzed, and then in step 88 the output from that program step is stored in the refresh memory 4.
is memorized. Next, in step 89, the ladder end is determined. Step 89 → Step 87 → Step 88 until the general ladder expression program ends.
→The operation of step 89 is repeated.

If the automatic/manual selector switch 7h is set to "manual", the process moves from step 80 to step 92.
The execution PC is set after STEP END of the step-by-step program, that is, after the end of step 007 (FIG. 7c). Then, in step 87, instructions and data in the storage area corresponding to the execution PC are read out, analyzed and executed, and the output is stored in the I/O refresh memory 4 in step 87. In this case, since "manual" is specified, reading and execution of the step-by-step program for automatic operation is skipped, and the program starts from the ladder expression program for manual operation. Then, following the ladder expression program for manual operation, step 89 → step 87 → step 88 → step until the general ladder expression program is completed.
89 actions are repeated.

When the ladder program is finished, whether the ``automatic'' or ``manual'' designation is selected, the flow moves from step 89 to step 90, where the ``output'' data stored in the I/O refresh memory 4 is used as a batch. After updating the output device and performing the specified operation processing (step 91),
Return to the beginning.

In the above embodiment, "automatic" and "manual" are designated by a changeover switch, but "automatic" and "manual" may be programmed in advance using command keys.

As described above, the step-by-step programmable controller of the present invention has at least a first program area for automatic operation using a step-by-step program and a second program area for manual operation using a ladder representation in the user program storage section. In addition, the program console section is provided with automatic/manual switching means, and when automatic operation is specified by the operation switching means, the central processing unit switches the program for automatic operation stored in the first program area. When manual operation is specified, the program for manual operation stored in the second program area is read and executed, so that not only sequence control but also a large number of inputs due to manual operation can be performed. In this way, it is possible to obtain a step-by-step programmable controller that can perform multiple processes and is very convenient to use.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a programmable controller system in which this invention is implemented, Figure 2 is a diagram showing an example of process control, and Figure 3 is a diagram created using a ladder representation to sequentially control the process shown in Figure 2. Figure 4 is a diagram showing the program, and Figure 4 is a diagram showing the program that controls the process shown in Figure 2 in process step form.
The figure shows the control flow when operating with the step-by-step program shown in FIG. 4. Figure 6 shows the control flow when operating the process shown in FIG. 7 is a diagram showing the storage area arrangement of the user program RAM of the embodiment system shown in FIG. 1, and FIG. 8 is a diagram showing the program for implementing the program shown in FIG. FIG. 3 is a diagram showing a control flow when operating an example system. 1: CPU, 2: ROM for system program,
3: RAM for user program, 4: RAM for I/O refresh memory, 5: For work area
RAM, 6: Input/output control section, 7: Program console section, 7h: Automatic/manual changeover switch, 8: Bus, 9: Input interface, 10:
Output interface, 11: I/O bus, 12:
Input terminal block, 13: Output terminal block.

Claims (1)

[Scope of Claims] 1. A program console section, a system program storage section, a user program storage section that stores a step-by-step program and a ladder representation program, and a system program according to the system program stored in the system program storage section. , and a central processing unit that executes the user program to control the controlled device, wherein the user program storage section includes at least a first programmable controller for automatic operation based on the step-by-step program. A program area and a second program area for manual operation using a ladder representation are provided, and the program console section is provided with an automatic/manual operation switching means, and the central processing unit is configured to perform automatic operation by the operation switching means. reads and executes a program for automatic operation stored in the first program area when specified, and executes a program for manual operation stored in the second program area when manual operation is specified. A step-by-step programmable controller characterized by reading and executing.