D-51 
 
 
Mnemonic Function 
LDP  Rising-edge detection operation 
Operand 
X0~X17 Y0~Y17 M0~M159  T0~15  C0~C7  D0~D29 
        
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Explanations: 
Usage of the LDP command is the same as the LD command, but the motion is different. It is used to 
reserve present contents and at the same time, saving the detection status of the acquired contact 
rising-edge into the accumulative register. 
 
Program Example: 
Ladder diagram:  Command code:  Operation: 
X1
Y1
X0
 
LDP  X0  Start X0 rising-edge detection 
AND  X1  Series connection A contact of X1 
OUT  Y1  Drive Y1 coil 
 
Mnemonic Function 
LDF  Falling-edge detection operation 
Operand 
X0~X17 Y0~Y17 M0~M159  T0~15  C0~C7  D0~D29 
        
--
 
Explanations: 
Usage of the LDF command is the same as the LD command, but the motion is different. It is used to 
reserve present contents and at the same time, saving the detection status of the acquired contact 
falling-edge into the accumulative register. 
Program Example: 
 
 
Ladder diagram:  Command code: Operation: 
X0 X1
Y1
LDF  X0  Start X0 falling-edge detection 
AND  X1  Series connection A contact of X1
OUT  Y1  Drive Y1 coil