User Manual Owner manual

Rockwell Automation Publication 1715-UM001C-EN-P - March 2014 137
Digital I/O Operation Chapter 3
Shutdown State
The output module shutdown state defines the behavior of the output module if
communications to the module fail within the timeout period or if the processor
is put into Program mode. This occurs on a channel-by-channel basis. These
principles apply for the 1715 analog and digital output modules.
The shutdown state can be configured to these values:
• On-energize
• Off-de-energize
• Hold last state
During normal operation with an adapter present, the state of the outputs can be
configured when no connections from a Logix controller are active.
Analog output modules can be configured to OFF, HOLD LAST VALUE, or
GOTO SPECIFIED VALUE.
In Shutdown mode, the analog output module will TURN OFF all channel
status indicators irrespective of the value being output.
Energize-on-communication-failure
The 1715 Redundant I/O System can be a part of an energize-on communication
failure system. This means that during a system fault, the output module can be
set so that the output is energized. This is on a point-by-point basis. The
following are examples of energize-to-trip uses:
• A fan that runs a ventilation system
• Emergency lights