Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual - Manual (Page 76)

Publication 1746-UM003A-EN-P
5-4 Ladder Programming Examples
Dynamic Programming The ladder below explains how to change data in the channel configuration
word when the channel is currently enabled.
Example - Execute a dynamic configuration change to channel 2 of the RTD
module located in slot 3 of a 1746 chassis. Change from monitoring the
temperature in °F to monitoring in °C.
Figure 5.4 Program to Change Configuration Word Data
Verifying Channel
Configuration Changes When executing a dynamic channel configuration change, there is always a
delay from the time the ladder program makes the change to the time the RTD
module gives you a data word using that new configuration information.
Therefore, it is very important to verify that a dynamic channel configuration
change took effect in the RTD module, particularly if the channel being
dynamically configured is used for control.
Example - Execute a dynamic configuration change to channel 2 of the RTD
module located in slot 3 of a 1746 chassis and set an internal “data valid” bit
when the new configuration has taken effect.
] [
COP
COPY FILE
Source
#N10:0
Dest #O:3.0
Length 8
S:1
15
Initialize RTD module First Pass Bit
On power up, bit S:1/15 is set for the first
program scan and integer file N10 is sent to
the RTD module channel configuration word.
] [
COP
COPY FILE
Source
#N10:0
Dest #O:3.0
Length 8
S:1
15
] [
0
I:1.0
END
( )
O:3.2
8
Set up all eight channels.
Set channel 2 to display in °C (off) or °F (on).
Rung 2:0
Rung 2:1
Rung 2:2