Allen-Bradley micrologix 1500 - GRT - Greater than LES - Less than

Publication 1762-RM001C-EN-P
9-4 Compare Instructions
GRT - Greater Than
LES - Less Than
Instruction Type: input
The GRT instruction is used to test whether one value is greater than a
second value. The LES instruction is used to test whether one value is less
than a second value.
GRT
Greater Than (A>B)
Source A N7:0
0<
Source B N7:1
0<
GRT
LES
Less Than (A<B)
Source A N7:0
0<
Source B N7:1
0<
LES
Table 9.4 Execution Time for the GRT and LES Instructions
Controller Data Size When Rung Is:
True False
MicroLogix 1200 word 1.3
µ
s1.1
µ
s
long word 2.8
µ
s2.7
µ
s
MicroLogix 1500 word 1.2
µ
s1.1
µ
s
long word 2.6
µ
s2.5
µ
s
Table 9.5 GRT and LES Instruction Operation
Instruction Relationship of Source Values Resulting Rung State
GRT A > B true
A
≤
Bfalse
LES A
≥
Bfalse
A
<
Btrue
IMPORTANT
Only use the High Speed Counter Accumulator (HSC.ACC)
for Source A in GRT, LES, GEQ and LEQ instructions.