|IN||VD, ID, QD, MD, SD, SMD, LD, AC, HC, Constant, *VD, *AC, *LD||DINT|
|OUT||VD, ID, QD, MD, SD, SMD, LD, AC, *VD, *AC, *LD||DINT|
|Memory Ranges||ENO||Errors||Instruction Support for S7-200 CPUs||SIMATIC/International Mnemonics|
|The Increment Double Word and Decrement Double Word instructions add or subtract 1 to or from the input double word (IN) and place the result in OUT.
In LAD and FBD: IN + 1 = OUT
IN - 1 = OUT
Increment and decrement double word operations are signed (16#7FFFFFFF > 16#80000000).
In STL: OUT + 1 = OUT
OUT - 1 = OUT
Error Conditions that Set ENO = 0:
SM1.1 (overflow), SM4.3 (run-time), 0006 (indirect address)
These instructions affect the following Special Memory bits:
SM1.0 (zero); SM1.1 (overflow); SM1.2 (negative)