The following is a list of the comparison instructions in SLC 500:
EQU - Equal.
NEQ - Not Equal.
LES - Less Than.
LEQ - Less Than or Equal.
GRT - Greater Than.
GEQ - Greater or Equal.
MEQ - Masked Comparison for Equal.
LIM - Limit Test.
When comparing two values, comparers are employed. Let's say we're comparing two physical quantities (temperature, pressure etc.). The equal command can be used to determine whether a first comparison value is equal to a second comparison value.
The Limit Test, or LIM, is an instruction that compares the provided operand to two limits: the lower limit and the upper limit. The instruction will set the output to TRUE if the value is larger than the lower limit and less than the upper limit.
When the test value is between the lower and upper limits of the lower and upper limits, the LIM instruction passes power.
To see if two values are equal, use the NEQ command.