Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 156)

Chapter 9
Using Comparison Instructions
9–5
Use the LES instruction to test whether one value (source A) is less than
another (source B). If the value at source A is less than the value of source B
the instruction is logically true. If the value at source A is greater than or
equal to the value of source B, the instruction is logically false.
Source A must be a word address. Source B can be either a constant or word
address. Negative integers are stored in two’s complement form.
Entering the Instruction
HHP Display Mnemonic
Function
Code
Use This Instruction When the Input:
LES LD LES 56 appears first on a rung or block
LES AND LES 57
is placed in series with any previous input
instruction in the current rung or block
LES
OR LES 58
is placed in parallel with any previous in-
put instruction in the current rung or block
You enter the instruction from within the program monitor functional area.
The example below shows how to enter the LD LES instruction. Use the
same procedure to enter the other LES instructions, only substitute the
function code with one from the table above.
P 0 0 0 L E S S R C A
N 1 1 0
P 0 0 0 L E S S R C B
1 0 0
24.00
False
23.60
True
6.60 LD LES
7.00 AND LES
24.00 7.00 OR LES
LES
LESS THAN
Source A
N7:11
0
Source B 100
Execution Times (
µ
sec) when:
Ladder representation:
Less Than (LES)
6
To enter the function code, press:
5
FUN ENT