Rockwell Automation 1747-ASB Remote I/O Adapter - Manual (Page 89)

Publication 1747-UM006B-EN-P - June 2003
Start-Up and Operation 6-3
Normal Operation During normal operation (PLC or SLC in Run mode), the 1747-ASB
module appears as shown below:
A communication exception is not an error because once the
exception is corrected, the 1747-ASB module begins normal operation
without the need to cycle remote chassis or remote expansion chassis
power. Communication exceptions are conditions that prevent
normal RIO link communications. They may even be purposely used
to change the operating state of the 1747-ASB module.
Communication Exception If a communication exception exists with one logical device under the
1747-ASB module's control, the 1747-ASB module treats all logical
devices under its control as if they too have the same condition. For
example, if one logical device is inhibited, the 1747-ASB module treats
all of its logical devices as if they too were inhibited.
Communication exceptions can only occur after the 1747-ASB module
has first received communications from the scanner for all of its
logical devices.
If the 1747-ASB module is more than one logical device, more than
one communication exception may be present at the same time. If
this occurs, they are handled on a priority basis.
Therefore, if one of the 1747-ASB module's logical devices is receiving
reset adapter decide commands and another is inhibited, the
1747-ASB module treats all of its logical devices under its control as if
they too were inhibited. Once the inhibit condition is cleared, the
module treats all of its logical devices as if they were receiving reset
adapter decide commands.
Status display
indicates a run
condition.
ADAPTER
COMM FAULT
STATUS
Red FAULT LEDS is off.
Green COMM LED is on.
Priority Condition
1 Loss of RIO link communications
2 Inhibits
3 Reset, adapter reset commands
4 Reset, adapter decide commands