User manual

High−level Instructions
3 − 92
Description
Subtracts 1 from the 32-bit data specified by D. The result is stored in D+1 and D.
Original data Result
(D+1, D) (D+1, D)− 1
Precautions during programming
If the result of an arithmetic operation instruction does not fall within the range of values which can be
handled, an underflow will result.
Under normal circumstances, do not allow an underflow to occur.
If an underflow occurs, the carry flag (special internal relay R9009) will turn on.
Flag conditions
・Error flag (R9007): Turns on and stays on when the area specified using the index modifier
exceeds the limit.
・Error flag (R9008): Turns on for an instant when the area specified using the index modifier
exceeds the limit.
・= flag (R900B): Turns on for an instant when the calculated result is recognized as “0”.
・Carry flag (R9009): Turns on for an instant when the calculated result exceeds the range of 32-bit
data (underflows).