Programmer (HHP) User guide

Chapter 9
Using Comparison Instructions
9–10
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.
Entering the Instruction
HHP Display Mnemonic
Function
Code
Use This Instruction When the Input:
LIM
LD LIM 71 appears first on a rung or block
LIM
AND LIM 72
is placed in series with any previous input
instruction in the current rung or block
LIM
OR LIM 73
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 LIM instruction. Use the
same procedure to enter the other LIM instructions, only substitute the
function code with one from the table above.
P
0 0 0 L I M L O W
4
P
0 0 0 L I M T E S T
N 0 0
P
0 0 0 L I M H I G H
1
LIM
LIMIT TEST
Low Lim 4
Test N7:0
0
High Lim 1
Execution Times (µ sec) when:
Ladder representation:
37.33
False
36.93
True
7.69LD LIM
8.09AND LIM
37.33 8.09OR LIM
Limit
T
es
t
(
LIM
)
7
1
ENT
FUN
To enter the function code, press: