Rockwell Automation 1746-XXXX SLC 500 4-Channel Analog I/O Modules User Manual - Manual (Page 50)

Publication 1746-UM005B-EN-P - June 2004
4-12 Module Operation and System Considerations
which exceed low and high limits respectively. For this example, the
analog input value is in word 1 of slot 1 (I1:1.1). Whenever the input
value exceeds a limit, this program latches a binary variable in
memory that could serve as an alarm indication at some other point in
the program.
The second program is for SLC 5/02 processors. This program uses the
Limit Test instruction that checks both low and high limits in a single
instruction. This instruction assumes that the analog input value is in
word 1 of slot 1 (I1:1.1).
As in the above program, whenever the input value exceeds a limit,
this program latches a binary variable in memory which could serve as
an alarm indication at some other point in the program.
GREATER THAN
Source A I1:1.1
Source B 16,384
LESS THAN
Source A I1:1.1
Source B 0
GRT
B3/0
(L)
B3/0
(L)
B3/0
(U)
END
Remainder of Program
Turn OFF
Alarm
Turn ON Alarm, Low Limit
Exceeded
Turn ON Alarm, High Limit
Exceeded
LES
LIM
B3/0
(L)
B3/0
(U)
END
Remainder of Program
Turn OFF
Alarm
Turn ON Alarm,
Limit Exceeded
LIMIT TEST (CIRC)
Low Lim 16,385
Test I1:1.1
High Lim ±1