When the execution result is 0, #L_CalcZero turns on.
If an overflow occurs as a result of the shift operation, the last overflowed bit is stored in #L_CalcCarry.
When the execution results in an error, the error information is stored in #L_Status.
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
SHL
Determines whether the most significant bit is ON or OFF.
When the variable of the positive transition instruction turns ON, the SHL instruction is run. When the SHL instruction is executed, the result of 1 bit shifted to the left is stored in D1.
When 1 bit is shifted to the left, you can check whether the most significant bit before data shifting is ON or OFF from the state of #L_CalcCarry.
When using a normally open instruction, the SHL instruction is always executed as long as the normally open bit is ON.
Program Example
SHLP
SHLP and SHL instructions have different ways of detecting when to execute. In SHLP instructions, even when using a normally open instruction, only the upward transition is detected and the SHLP instruction is executed. Even if the bit of the normally open instruction remains ON, the SHLP instruction is executed only for one scan.