When the execution result is 0, #L_CalcZero turns on.
When the execution results in an error, the error code is stored in #L_CalcErrCode.
When checking the result using system variables, make sure the check takes place after the instruction has been executed. When checking the state after multiple instructions have been executed, system variables will store the result only of the last processed instruction.
Program Example
ACOS
The ACOS instruction is executed when the positive transition instruction turns ON. The ACOS instruction calculates the arc cosine of Data_A and stores the result in D1.
When using a normally open instruction, the ACOS instruction is always executed as long as the normally open instruction bit is ON.
ACOSP
ACOSP and ACOS instructions differ in when they run. In ACOSP instructions, even when using a normally open instruction, the ACOSP instruction executes only when it detects the upward transition. Therefore, the ACOSP instruction is executed only for one scan, even when the normally open instruction bit remains ON.