Rockwell Automation GMLC Reference Manual - Manual (Page 506)

Publication GMLC-5.2 - November 1999
Expression Operators 469
Specifically, if inputs 2 - 5 are currently in the following states, the
expression above is evaluated as 11 (1001
2
| 0010
2
= 1011
2
= 11
10
).
Input 2 = ON
Input 3 = OFF
Input 4 = OFF
Input 5 = ON
Boolean NOT
!
Use the exclamation point to complement a single-bit (Boolean) logic
element. This is especially useful for forming logical expressions
involving status bits, discrete I/O, timers, etc. For example, the following
expression has a value of 1(true) if currently there is not a hardware
overtravel fault condition on Axis 0 (neither of the overtravel limit switch
inputs for Axis 0 is active).
!Hardware_overtravel_fault_AXIS0
Boolean AND
&&
Use the double ampersand to logically AND together two Boolean (single-
bit) logic elements. This is especially useful for forming logical
expressions involving status bits, discrete I/O, timers, etc. For example,
the following expression has a value of 1(true) only when both input 8
and input 9 are
ON .
Input_8 && Input_9
Boolean OR
||
Use the double pipe (vertical bar) to logically OR together two Boolean
(single-bit) logic elements. This is especially useful for forming logical
expressions involving status bits, discrete I/O, timers, etc. For example,
the following expression has a value of 1(true) when there is currently a
drive fault condition (drive fault input active) on Axis 0 or Axis 1.
Drive_fault_AXIS0 || Drive_fault_AXIS1