Rockwell Automation 1746-NT4 Series B,D17466.6.1 SLC 500 4-Channel Thermocouple/mV Input Module User Manual - Manual (Page 74)

Publication 1746-UM007C-EN-P - July 2004
6-4 Ladder Programming Examples
Verifying Channel
Configuration Changes When executing a dynamic channel configuration change, there will
always be a delay from the time the ladder program makes the change
to the time the NT4 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 NT4
module, particularly if the channel being dynamically configured is
used for control. The following example explains how to verify that
channel configuration changes have taken effect.
Example - Execute a dynamic configuration change to channel 2 of
the thermocouple module located in slot 3 of a 1746 chassis, and set
an internal “data valid” bit when the new configuration has taken
effect.
Program Listing
] [
COP
COPY FILE
Source
#N10:0
Dest #O:3.0
Length 4
S:1
15
Set up all four channels. Rung 2:0
] [
0
Set channel 2 to CJC. Rung 2:1
B3
0
I:1.0
[OSR]
MOVE
Source
N10:4
Dest O:3.2
MOV
Rung 2:2
B3
1
]/[ MOVE
Source
N10:2
Dest O:3.2
Set channel 2 back to type K.
MOV
0
I:1.0
[OSR]
Rung 2:3
EQUAL
Source A
I:3.6
Source B O:3.2
Check that the configuration written to channel 2 is
being echoed back in channel 2's status word.
EQU
( )
B3
3
Data valid
Rung 2:4
END
Data Table
address 15 data 0 address 15 data 0
N10:0 0000 1001 0001 0001 N10:3 0000 1001 0001 0001
N10:1 0000 1001 0001 0001 N10:4 0000 1001 0001 1111
N10:2 0000 1001 0001 0001