3. Instruction Set
API
Mnemonic Operands Function
SS2
SX2
25 D
DEC P
Decrement
Type
OP
Bit Devices Word devices Program Steps
X Y M S K H KnX
KnY
KnM
KnS
T C D E F
DEC, DECP: 3 steps
SS2
SX2
SS2
SX2
SS2
SX2
Operands:
D: Destination device
Explanation:
1. If the instruction is not used in pulse execution mode, the content in the designated device D
will minus “1” in every scan whenever the instruction is executed.
2. This instruction is generally used in pulse execution mode (DECP, DDECP).
3. In 16-bit instruction, if –32,768 is reached and “1” is minused, it will write a value of +32,767 to
the destination. In 32-bit instruction, if -2,147,483,648 is reached and “1” is minused, it will
write a value of +2,147,483,647 to the destination.
4. If operand D uses index F, only a 16-bit instruction is applicable.
5. The operation results will not affect M1020 ~ M1022
Program Example:
When X0 is triggered, the value in D0 will be decremented by 1.