Rockwell Automation T3485 ICS Regent Isolated Guarded Output Modules - Manual (Page 8)

Isolated Guarded Digital Output Module (T3485)
8
Industrial Control Services
Shutdown Indicator
Upon loss of communications with the controller, output
modules enter either a shutdown or hold fault mode. If the I/O
unit is set to shutdown, the red SHUTDOWN
indicator will
turn on when communications with the controller are lost. If
the I/O unit is set to hold, the SHUTDOWN indicator will
always be off (see page 15, Fault Mode Jumper).
When the module is installed in the I/O chassis or when logic
power (from the I/O power supply modules) is first applied to
the module, it will be in the shutdown mode until the first
output scan, regardless of the fault mode jumper settings.
Also, removing two I/O transceiver modules, two I/O power
supply modules, or two power legs will cause the module to be
in the shutdown mode.
Output Status Indicators
The output status indicators are yellow LEDs, located on the
front of the module. The FPGAs logically drive the output
status LEDs. The indicator is on when both of the FPGAs
agree that the output circuit is energized.
The blown fuse indicators are red LEDs. When a blown fuse is
detected the LED is energized. Under certain operating
conditions, a blown fuse may not be detected. For more
information see Output Fuse Monitoring, on page 5.
Application
Isolated Guarded output modules provide a suitable interface
to safety-critical output devices. These safety-critical devices
typically include motor starters, motor operated valves or
other output circuits operating from isolated power sources.
Isolated Guarded output modules can be used for fail-safe or
fault tolerant operation.
Fail-Safe Configuration
As shown in Figure 4, fail-safe configuration uses a single
isolated Guarded output module. In this configuration, the
worst case failure will cause the output to fail to the off state.
Note: