Precautions When Using A Control Instruction - Panasonic FP0 User Manual

Precautions During Programming
8.5 Instruction of Leading Edge Detection Method
8.5.3

Precautions When Using a Control Instruction

Instructions which leading edge detection compare the condition of the previous
execution and the condition of the current execution, and execute the instruction only
if the previous condition was off and the current condition is on. In any other case, the
instruction is not executed.
When a leading edge detection instruction is used with an instruction which changes
the order of instruction execution such as MC, MCE, JP or LBL, the operation of the
instruction may change as follows depending on input timing. Take care regarding this
point.
Example 1:
Using the DF instruction between MC and MCE instructions
Time chart 1
Time chart 2
8 − 16
X0
X1
DF
X0
X1
Y0
Previous
The input condition (X1) for the DF instruction has
execution of DF
not changed since the time of the previous
instruction
execution, thus derivative output is not obtained.
X0
X1
Y0
Previous
The input condition (X1) for the DF instruction has
execution of DF
changed from off to on since the time of the previous
instruction
execution, thus derivative output is obtained.
MC 0
Y0
MCE 0
FP0