If an overflow occurs as a result of the instruction, the system variable (bit) #L_CalcCarry turns on.
#L_Error turns on, and the error code (6706) is written to #L_CalcErrCode.
When the execution result is 0, the system variable #L_CalcZero turns ON.
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
MOD
Performs modules operation on two constants and stores the result in the integer variable.
When the positive transition instruction turns ON, the MOD instruction will be executed. When the MOD instruction is executed, the result value of 10, obtained from 25/15 = 1 (remainder 10), is stored in D1.
When using a normally open instruction, as long as the operation is ON, the MOD instruction is always executed.
MODP
When the normally open instruction turns ON, the MODP instruction is executed. When the MODP instruction is executed, the result value of 10, obtained from 25/15 = 1 (remainder 10), is stored in D1.
Even when using a normally open instruction, the MODP instruction executes only when it detects the upward transition.
Therefore, even when the NO instruction is always ON, the MODP instruction is executed only for one scan.