Chapter 16 PLC Function ApplicationsC2000 Plus
16-43
16-6-2 Detailed explanation of basic commands
Command Function
LD
Load contact a
Operand
X0–X17 Y0–Y17 M0–M799 T0–159 C0–C79 D0–D399
-
The LD command is used for contact a starting at the left busbar or contact a starting
at a contact circuit block; its function is to save current content and save the acquired
contact status in the cumulative register.
Ladder diagram:
X0
X1
Y1
Command code: Description:
LD X0
Load Contact a of X0
AND X1
Create series
connection to contact a
of X1
OUT Y1 Drive Y1 coil
Command Function
LDI
Load contact b
Operand
X0–X17 Y0–Y17 M0–M799 T0–159 C0–C79 D0–D399
-
The LDI command is used for contact b starting at the left busbar or contact b starting
at a contact circuit block; its function is to save current content and save the acquired
contact status in the cumulative register.
Ladder diagram:
X0
X1
Y1
Command code: Description:
LDI X0
Load Contact b of X0
AND X1
Create series
connection to contact a
of X1
OUT Y1 Drive Y1 coil
Command Function
AND
Connect contact a in series
Operand
X0–X17 Y0–Y17 M0–M799 T0–159 C0–C79 D0–D399
-
The AND command is used to create a series connection to contact a; first reads
current status of the designated series contact and logical operation results before
contact in order to perform "AND" operation; saves results in cumulative register.
Ladder diagram:
X1
X0
Y1
Command code: Description:
LDI X1 Load Contact b of X1
AND X0
Create series
connection to contact a
of X0
OUT Y1 Drive Y1 coil
Command Function
ANI
Connect contact b in series
Operand
X0–X17 Y0–Y17 M0–M799 T0–159 C0–C79 D0–D399
-
The ANI command is used to create a series connection to contact b; its function is to first read
current status of the designated series contact and logical operation results before contact in
order to perform "AND" operation; saves results in cumulative register.
Ladder diagram:
X0
X1
Y1
Command code: Description:
LD X1
Load Contact a of X1
ANI X0
Create series connection
to contact b of X0
OUT Y1
Drive Y1 coil