JPS61807A - Sequence controller - Google Patents

Abstract

PURPOSE:To facilitate easy programming even with a complicated sequence including the branching, the queuing, etc. by delivering a state input instruction and a state shift instruction and controlling the shifts among plural control states by means of an input condition table. CONSTITUTION:When operands R1 and R2 of state input instructions 200 and 201 are turned on at a time, both operands are registered to an input condition register table together with an output turned on. When the external input conditions X1 is turned on under such conditions, the input signal of a state shift instruction 210 is turned on. As a result, an operand R3 is turned on with operands R1 and R2 turned off. The control state is shifted to the R3 from the R1 and R2. When the R3 is turned on, the operand R3 of a state input instruction 202 is registered to the input condition table. Then the output of the table is turned on together with the external input conditions X2 or X3 turned on respectively. Then the input signal of a state shift instruction 211 or 212 is turned on. Thus an operand R4 or R5 is turned on, and the control state is changed to the R4 or R5 from the R3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a sequence controller that has a control function that allows complicated sequences including waiting, branching, etc. to be easily completed.

[Technical background of the invention and its problems]

7. The controller performs control processing according to a program that describes sequence control operations.
As a programming language, a ladder diagram method as shown in FIG. 8 is generally used.

For example, the ladder diagram is displayed corresponding to a contact circuit including the A contact 1, the B contact 2, and the relay coil 3 as shown in Fig. A state transition display like the one shown in the figure (-) may be easy to separate.

In other words, in FIG. 9, state 10 is used as the base point of the control operation, and when condition a is satisfied, state 11 is reached, and similarly, when condition a is established, condition b is established.
+C+...When X is established, states 12゜13・
..., Nl=transition, each state (=corresponding operations such as opening/closing the valve and starting/stopping the motor are performed, and then the state I
N=Return and the above operation is repeated.

FIG. 10 shows a sequence in which a plurality of control operations proceed in parallel, and in this case, after the state addition, condition a is established (=therefore, three states 21, 24, 271=branch, and further (=Sequences proceed in parallel according to each condition.

Further, states 5 and 29 wait for states B and 5 or state A, respectively, and proceed when conditions e and g are satisfied, respectively.

However, since conventional sequence controller programs are based on the ladder diagram contradictory system as shown in Figure 8, it is easy to program the sequence shown in Figure 9 above, but it is easy to program the sequence shown in Figure 10. Programming is difficult if the waiting list is complex and has a large group of people.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a ladder diagram type sequence controller (-) that has a control function that allows easy programming of sequences including branching and waiting.

[Summary of the invention]

The present invention includes an input condition registration table that registers a plurality of operands specifying input conditions in a sequence controller programmed in a ladder diagram, and an output signal 42 that reflects the operand status and turns the operand status on. When the condition input command registers the second operand in the input condition registration table above, and when the condition judgment result by the ladder diagram program is ON, the specified operand is set and the input condition registration table (= registration It is equipped with a state transition instruction that resets all operands in the control state. It is something.

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG.

In FIG. 1, boxes 200 to 202 are state input commands each having internal coils R1 to R3 of the sequence controller as operands, and boxes 210 to 21
2 is a state transition command each having internal coils R3 to R5 as operands, contact signals X1 to X3 are external input conditions sb for determining state transition conditions, and FIG. 1 shows a sequence program in the form of a ladder diagram.

Figure 2 shows the program in Figure 1 in a state transition format. It waits for R1 and R2, moves to R3 under external input condition X1, and branches to R4 and R5 under external input conditions X2 and X3, respectively. ], which represents exactly the same sequence as the ladder diagram in Figure 1.

FIG. 3 shows status input commands 200 to 202 in FIG.
and shows the word structure of the state transition instructions 210 to 212, which are composed of an instruction function code 301 and an operand 302 indicating the address of the control state.

The CPU of the sequence controller decodes the above instruction and executes the instruction.

FIG. 4 is an input condition registration table provided on the memory of the sequence controller. When a state input command is executed, addresses of operands corresponding to active control states are registered.

The line 312 at the top of the input condition registration table 311 is a control flag for registration, which is turned on when a state input command is executed and turned off when a state transition command is executed.

The next CNT 313 is performed after the CNT (one by one input condition registration unit 314 (=a counter that holds the number of registered operands; registration is performed in order from the top).

FIG. 5 is a flowchart showing the control function that the CPU decodes and executes as a state input command.
Taking 01 as an example, first, when the input signal on the left side of the box is off, the output signal on the right side is turned off.

The left input signal and FLG are on! ri (FLG
is off, turn it on and set CNT to 0), and if the operand of the instruction (R2 in this case) is on, register the address of the operand in the input condition registration table in Figure 4 (register the address of the operand and set CNT to 0). 1 and turn on the output signal C2.

If the operand is off, turn off the output signal.

FIG. 6 is a flowchart showing the control function for the CPU to decode and execute the state transition instruction.
For example, if we take 10 (=), first turn off FLG, and if the input signal on the left side of the box turns on, the operand of the instruction
(Here, R3) is turned on, and if the content of CNT is not 0 (in this case, if the input signal is on, R1
, R2 are always on, so CNT is 2).

If the input signal is off, the above operation is not performed and the control flag is simply turned off.

Using the above control functions, the program of FIG. 1 is executed as follows.

When the operands R1 and R2 of the state input instructions 200 and 201 are both ((=) in FIG. 1, the operands R1 and R2 are registered in the input condition registration table according to the procedure shown in FIG. d.

When the external input condition XI turns on in this state, the input signal of the state transition instruction 210 turns on, so according to the procedure shown in FIG. 6, the operand R3 turns on and is simultaneously registered in the input condition registration table. Operand R1, R2
is turned off, and the control states are R1 and R2 due to this ζ2.
to R3.

If even one of R1 and R2 is off, the state transition command 2100 input signal is off), and therefore no control state transition occurs.

When R3 is turned on, the operand R3 of the status input instruction 202 that uses R3 as an operand is input to the input condition registration table (
- If it is registered and its output is on, external input condition
2 or x3 turns on (=, the input signal of the state transition instruction 211 or 212 turns on (turns on, and the operation 2
Alternatively, R5 is turned on and the control state shifts from R3 to R4 or R5.

The program shown in FIG. 1 is executed by the above control operations.

FIG. 7 shows an example of another program using the present invention. In circuit 1, instead of waiting for states R1 and R2, one of the states is the contact signal XI, X, respectively.
2 to state R3, and in circuit 2, state R3
is on, states R4, R5, R with contact X3 as the condition.
i Two transitions at the same time.

In addition, in circuit 3, states R4 and R5 switch their contacts to state MR7 as an interlock condition. It shows that it can be programmed in another representation format.

〔Effect of the invention〕

As explained above, the second aspect of the present invention is to provide a state input command and a state transition command, and use an input condition table to control the transition between multiple control states. It is possible to realize a rational sequence controller that can be easily programmed even for complex sequences including one waiting branch, simultaneous parallel progress, etc.

[Brief explanation of the drawing]

FIG. 1 is a program diagram showing an embodiment of the present invention, FIG. 2 is a state transition diagram equivalent to the program in FIG. 1, FIG. 3 is a diagram showing the implicit word structure of the instructions in the present invention, and FIG. is a diagram showing an example of an input condition registration table used in the present invention, FIGS. 5 and 6 are flowcharts respectively showing the execution procedure of the state input command and state transition command in the present invention, and FIG. 7 is a diagram showing an example of the input condition registration table used in the present invention. FIG. 8 is a diagram showing an example of a program of the conventional sequence controller 2, and FIGS. 9 and 10 are diagrams each showing various sequences in terms of state transitions. 200-204 State input commands 210-214 State transition commands 300 Command words 311 Human power condition registration tables X1-X3
Contact input signal (8733) Agent: Yoshiaki Inomata, patent attorney (and 1 others)
Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] In a sequence controller programmed using a ladder diagram, there is an input condition registration table that registers multiple operands that specify input conditions, and an input condition registration table that reflects the operand status in the output signal and when the operand status is on, the operand is set to the above input condition. A state input command registered in the registration table and a state transition that sets the specified operand when the condition judgment result by the ladder diagram program turns on and resets all operands registered in the input condition registration table above. 1. A sequence controller comprising instructions for controlling state transition between a plurality of control states.