Rockwell Automation 1797-ACNR15 ControlNet Ex Redundant Media Adapter - Manual (Page 12)

12 ControlNet Ex Redundant Media Adapter
Publication 1797-5.14 - March 2010
ControlNet Ex Adapter Operation
The ControlNet Ex adapter, combined with FLEX Ex output modules,
provides a two-tier fault state mechanism. It is important to consider and
understand the operation of this mechanism when designing your system.
Two sets of programmable fault states are available, one each in the adapter
and output module. This two-tier method is meant to give you a wider fault
coverage compared with normal methods.
Network Communication Monitoring
The adapter is the primary monitor of network activity. If it detects loss of
network communication, it can be programmed to:
• continue writing the last valid received data to the module (hold last
state).
• apply local module safe states. (1)
• write a programmable fault state value to the module, depending upon
the module type.
This mechanism primarily targets fault behavior for loss of network
communication.
Program Mode Behavior
The adapter also monitors the state of the controlling processor or scanner.
Two states can be detected: Run mode and Program mode (idle).
When run mode is detected, the adapter writes the output data received from
the processor to the corresponding module output.
When Program mode is detected, the adapter can be configured to:
• continue writing the last valid received data to the module (hold last
state).
• apply local module safe states to zero. (1)
• write a programmable fault state value to the module, depending upon
the module type.
(1) This selection is shown as Reset Outputs in RSNetWorx software but its action is Apply Local Module
Safe States.