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