Rockwell Automation 1747-ASB Remote I/O Adapter - Manual (Page 90)

Publication 1747-UM006B-EN-P - June 2003
6-4 Start-Up and Operation
Inhibit Condition
When any of the 1747-ASB module's logical devices are inhibited
before communication with all of its logical devices occur at least
once:
•
The inhibited logical devices do not communicate on the RIO
link.
•
The enabled logical devices communicate on the RIO link.
•
The 1747-ASB module does not send output data to any of its
output modules, even those that are enabled.
•
The 1747-ASB module does not process any RIO block transfer
writes.
•
The 1747-ASB module sends new input data from its input
modules to the scanner for enabled devices.
•
The 1747-ASB module processes RIO block transfers reads for
enabled devices.
The position of the processor restart lockout switch (PRL) affects the
1747-ASB module's inhibit functionality. If processor restart lockout is
selected, and any logical device assigned to the 1747-ASB module is
inhibited after all of the logical devices have received RIO link
communications from the scanner at least once:
•
All of the 1747-ASB module's logical devices stop
communicating on the RIO link.
•
The 1747-ASB module does not send any output data to any of
its output modules.
•
Discrete outputs are held in their last state if hold last state is
selected, or discrete outputs are reset if hold last state is not
selected.
•
The 1747-ASB module does not process any RIO block transfers.
If processor restart lockout is not selected and any logical device
assigned to the 1747-ASB module is inhibited after all of the logical
devices have received RIO link communications from the scanner at
least once:
•
The inhibited logical devices stop communicating on the RIO
link.
•
The enabled logical devices continue to communicate on the
RIO link.
•
The 1747-ASB module does not send new output data to any
logical device output module, even those that are enabled.