Rockwell Automation 1798-IB4 FlexArmor User Manual - Manual (Page 18)

Publication 1798-UM001B-EN-P - November 2002
2-4 How Communication Takes Place and I/O Image Table Mapping
Possible causes for an I/O Module Fault are:
•
transmission errors on the FlexArmor backplane
•
a failed module
•
a module removed from the FlexArmor Baseplate
•
incorrect module inserted in a slot position
•
the slot is empty, but the platform is configured for a module in
the slot location
Communication Choices The FlexArmor DeviceNet adapter module supports multiple
communication choices. These choices all use the default I/O
structure previously described. The adapter master makes the actual
communication choice. The choices are:
Polled - data is sent by the adapter in response to received data
Strobe - data is sent by the adapter in response to the strobe
command. The single bit allocated to the adapter in the strobe
message is not used. If the configured size of the input data (sent from
the adapter) is greater than 8 bytes, the strobe connection
establishment will fail. In this case, the input size must be
re-configured to 8 bytes or less.
Change of State - data is sent by the adapter based on detection of
any changed value within the input data. Data is independently
received based on change of state from the sender. Data in both
directions can be acknowledged or unacknowledged depending on
the run time configuration of the system.
Cyclic - data is sent cyclically by the adapter based on a configured
time value. Data is independently received cyclically from the sender.
Data in both directions can be acknowledged or unacknowledged
depending on the run time configuration of the system.