Rockwell Automation 1746-NR4 SLC RTD/Resistance Input Module User Manual - Manual (Page 21)

Publication 1746-UM008B-EN-P - December 2006
Overview 21
The status of each LED indicator, during each of the operational states
(for example, powerup, module operation and error), is depicted in
the following table.
Module to Processor Communication
The RTD module communicates with the SLC processor through the
backplane of the chassis. The RTD module transfers data to and
receives data from the processor by means of an image table. The
image table consists of eight input words and eight output words.
Data transmitted from the module to the processor is called the input
image (for example, Channel Data Words and Channel Status Words).
Conversely, data transmitted from the processor to the module is
called the output image (for example, Channel Configuration Words
and Scaling Limit Words).
Details about the input and output images are found in Module
Addressing on page 52 and 53.
Communication Flow
LED Indicator Status
LED Indicator Cycle
Power Module Operation
(No Error) Module Error Channel
Error
Ch 0 Status
Off
(1)
(1) Module is disabled while you cycle module power.
On/Off
(2)
(2)
Channel status LED indicator is ON if the respective channel is enabled and OFF if the channel is disabled.
Off Blinks
Ch 1 Status
Off
(1)
On/Off
(2) Off Blinks
Ch 2 Status
Off
(1)
On/Off
(2) Off Blinks
Ch 3 Status
Off
(1)
On/Off
(2) Off Blinks
Mod. Status
Off
(1) On Off On
Channel Data Words
Channel Status Words
Scaling Limit Words
Channel Configuration Words
SLC 500
Processor
1746-NR4
Input
Module
RTD/
resistance
Analog
Signals