GE PACSystems RX7i

Chapter 4. Ladder Diagram (LD) Programming
GFK-2950C February 2018 77
4.2.7 Logical NOT
When the Logical Not or Logical Invert (NOT) function receives power flow, it sets the state of each
bit in the output bit string Q to the opposite of the state of the corresponding bit in bit string IN1.
All bits are altered on each scan that power is received, making output string Q the logical
complement of input string IN1. Logical NOT passes power flow to the right whenever it receives
power. You can specify a string length of 1 to 256 WORDs or DWORDs
Operands for Logical NOT
Parameter
Description
Allowed Operands
Optional
Length (??)
The number of WORDs or DWORDs in
the bit string to NOT. 1  Length 
256.
Constant
No
IN1
The first WORD or DWORD of the
input string to NOT.
All
No
Q (Must be the same data
type as IN1)
The first WORD or DWORD of the
NOT's result.
All except constants and
variables located in %S memory
No
Example
When input V_I0001 is set, the bit string represented by the variable A is negated. Logical NOT stores
the resulting inverse bit string in variable B. Variable A retains its original bit string value.