Programming

Appendix A

Since condition flags are shared by all instructions, make absolutely sure that they do not interfere with each other within a single ladder-diagram program. The following are examples.

1.Using Execution Results in NC and NO Inputs

The Condition Flags will pick up instruction B execution results as shown in the example below even though the NC and NO input bits are executed from the same output branch.

Incorrect Use

Instruction A

Reflects instruction A Condition Flag execution results. Example: =

Instruction B

Reflects instruction B Condition Flag execution results. Example: =

Make sure each of the results is picked up once by an OUTPUT instruction to ensure that execution results for instruction B will be not be picked up.

Correct Use

Reflects instruction A

Instruction A

 

execution results.

 

Condition Flag

C

Example: =

 

Reflects instruction A

Condition Flag

execution results.

Example: =

D

C

Instruction B

D

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Omron FQM1-MMP21, FQM1-CM001, FQM1-MMA21 operation manual Using Execution Results in NC and no Inputs