Chapter 16 PLC Function Applications│CP2000 
 
16-49
Command  Function 
LDP 
Start of forward edge detection action   
Operand   
X0–X17  Y0–Y17  M0–M799  T0–159  C0–C79  D0–D399 
         
- 
 
The LDP command has the same usage as LD, but its action is different; its function is 
to save current content, while also saving the detected state of the rising edge of the 
contact to the cumulative register.   
 
Ladder diagram:   
X1
Y1
X0
 
Command   
code:   
Description: 
LDP  X0 
Start of X0 forward edge detection 
action   
AND 
X1 
Create  series  connection  to 
contact a of X1   
OUT  Y1  Drive Y1 coil   
 
Please refer to the function specifications table for each device in series for the scope 
of usage of each operand.   
 rising edge contact will be TRUE after power is turned on if the rising edge contact is 
On before power is turned on to the PLC.   
 
Command  Function 
LDF 
Start of reverse edge detection action   
Operand   
X0–X17  Y0–Y17  M0–M799  T0–159  C0–C79  D0–D399 
         
- 
 
The LDF command has the same usage as LD, but its action is different; its function is 
to save current content while also saving the detected state of the falling edge of the 
contact to the cumulative register.   
 
Ladder diagram:   
X1
Y1
X0
 
Command code:    Description: 
LDF  X0 
Start  of  X0  reverse 
edge detection action   
AND 
X1 
Create  series 
connection to contact a 
of X1   
OUT  Y1  Drive Y1 coil   
 
Command  Function 
ANDP 
Forward edge detection series connection   
Operand   
X0–X17  Y0–Y17  M0–M799  T0–159  C0–C79  D0–D399 
         
- 
 
The ANDP command used for a contact rising edge detection series connection.   
 
Ladder diagram:   
X1
Y1
X0
 
Command code:    Description: 
LD  X0  Load Contact a of X0   
ANDP 
X1 
X1 Forward edge 
detection series 
connection   
OUT  Y1  Drive Y1 coil