Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 169)

3 Basic Instructions
DVP-PLC Application Manual 3-15
END instruction has to be placed in the end of a ladder diagram or instruction program. PLC will start to scan from
address 0 to END instruction and return to address 0 to restart the scan.
Mnemonic Function Program steps
NOP No operation 1
Controllers
ES EX SS SA SX SC EH SV
Operand N/A
Explanations:
NOP instruction does not conduct any operations in the program; therefore, after the execution of NOP, the existing
logical operation result will be kept. If you want to delete a certain instruction without altering the length of the program,
you can use NOP instruction.
Program Example:
Ladder diagram: Instruction code: Operation:
LD X0 Loading in B contact of X0
NOP No operation
X0
Y1 NOP
NOP instruction will be
omitted in the ladder diagram
OUT Y1 Driving Y1 coil
Mnemonic Function Program steps
INV Inverting Operation 1
Controllers
ES EX SS SA SX SC EH SV
Operand N/A
Explanations:
The logical operation result before INV instruction will be inverted and stored in the accumulative register.
Program Example:
Ladder diagram: Instruction code: Operation:
LD X0 Loading in A contact of X0
INV Inverting the operation result
X0
Y1
OUT Y1 Driving Y1 coil
Mnemonic Function Program steps
P Pointer 1
Controllers
ES EX SS SA SX SC EH SV
Operand P0 ~ P255
Explanations:
Pointer P is used in API 00 CJ and API 01 CALL instructions. The use of P does not need to start from No. 0, and the
No. of P cannot be repeated; otherwise, unexpected errors may occur.