Rockwell Automation T7420A_AF ICS Regent+Plus Analog Input Modules 60Hz Rejection and Fast Response - Manual (Page 4)

Analog Input Modules (T7420A, AF)
4
Industrial Control Services
produces an I/O module error indication at the processor
modules and a module fault indication at the I/O module.
Each type of module has a unique identification code that is
read by the controller. This code lets the controller know
which type of module is installed in each I/O chassis slot and
how to address that module and its points specifically. If a
module is removed, or is replaced with a module of a different
type, the processor modules will indicate an I/O module error.
Loopback logic tests periodically write data to the module and
then read it back to determine whether the module’s I/O bus
interface logic is functioning correctly.
Front Panel Indicators
Figure 3 shows the physical features of the analog input
modules. The front panel of each module contains active and
fault status indicators.
Active and Fault Status Indicators
These green and red LEDs indicate the overall health of the
module. During normal operation the green ACTIVE
indicator flashes at the controller's scan rate. If a module
fault occurs the red FAULT indicator turns on and the green
ACTIVE indicator turns off.