Siemens S7-1200 - NEG (Create Twos Complement) Instruction; INC (Increment) and DEC (Decrement) Instructions

Basic instructions
7.5 Math functions
S7-1200 Programmable controller
232 System Manual, 03/2014, A5E02486680-AG
7.5.4
NEG (Create twos complement) instruction
Table 7- 44 NEG (create twos complement) instruction
LAD / FBD
SCL
Description
-(in);
The NEG instruction inverts the arithmetic sign of the value at parameter IN and stores
the result in parameter OUT.
1
For LAD and FBD: Click the "???" and select a data type from the drop-down menu.
Table 7- 45 Data types for parameters
Parameter
Data type
1
Description
IN
SInt, Int, DInt, Real, LReal, Constant
Math operation input
OUT
SInt, Int, DInt, Real, LReal
Math operation output
1
The IN and OUT parameters must be the same data type.
Table 7- 46 ENO status
ENO
Description
1 No error
0 The resulting value is outside the valid number range of the selected data type.
Example for SInt: NEG (-128) results in +128 which exceeds the data type maximum.
7.5.5
INC (Increment) and DEC (Decrement) instructions
Table 7- 47 INC and DEC instructions
LAD / FBD
SCL
Description
in_out := in_out + 1;
Increments a signed or unsigned integer number value:
IN_OUT value +1 = IN_OUT value
in_out := in_out - 1;
Decrements a signed or unsigned integer number value:
IN_OUT value - 1 = IN_OUT value
1
For LAD and FBD: Click the "???" and select a data type from the drop-down menu.