Rockwell Automation 1794-IF4I, -OF4I, IF2XOF2I, -IF4IXT, -IF4ICFXT, -OF4IXT, IF2XOF2IXT FLEX I/O Isolated Analog Modules - Manual (Page 102)

Publication 1794-6.5.8 - January 2010
102 Input, Output, Status and Configuration Files for Analog Modules when used with ControlNet
Possible causes for an I/O Module Fault are:
•
transmission errors on the FLEX I/O backplane
•
a failed module
•
a module removed from its terminal base
•
incorrect module inserted in a slot position
•
the slot is empty
Safe State Data The ControlNet adapter provides the non-discrete module output data
during communication faults or processor idle state. This “safe state
data” assures that a known output will be applied to the output
devices to maintain a previously designated safe operating condition
during the previously mentioned failure modes. The processor or
scanner software must include the means to specify this safe state data
for each non-discrete module.
Communication Fault
Behavior You can configure the adapter response to a communication fault for
each I/O module in its system. Upon detection of a communication
fault, the adapter can:
•
leave the module output data in its last state (hold last state)
•
reset the module output data to zero (reset)
•
apply safe state data to the module output
Idle State Behavior The ControlNet adapter can detect the state of the controlling
processor or scanner. Only 2 states can be detected: run mode, or
program mode (idle).
When run mode is detected, the adapter copies the output data
received from the processor to the corresponding module output.
When program mode is detected, the adapter can be configured to:
•
leave the module output data in its last state (hold last state)
•
reset the module output data to zero (reset)
•
apply safe state data to the module output