Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 128)

Preface MicroLogix 1000 Programmable Controllers User Manual
7–6
Limit Test (LIM)
Use the LIM instruction to test for values within or outside a specified range,
depending on how you set the limits.
Entering Parameters
The Low Limit, Test, and High Limit values can be word addresses or constants,
restricted to the following combinations:
•
If the Test parameter is a constant, both the Low Limit and High Limit
parameters must be word addresses.
•
If the Test parameter is a word address, the Low Limit and High Limit
parameters can be either a constant or a word address.
True/False Status of the Instruction
If the Low Limit has a value equal to or less than the High Limit, the instruction is
true when the Test value is between the limits or is equal to either limit. If the Test
value is outside the limits, the instruction is false, as shown below.
Example, low limit less than high limit:
Low
Limit
High
Limit
Instruction is True
when Test value is
Instruction is False
when Test value is
5 8 5 through 8 –32,768 through 4 and 9 through 32,767
False True False
–32,768
Low Limit High Limit
+ 32,767
Execution Times
(
µ
sec) when:
True False
36.93 7.69
LIM
LIMIT TEST
Low Lim
Test
High Lim