Allen-Bradley PLC-5 User Manual page 82

6-10 Communicating with Remote I/O
Publication 1785-UM012D-EN-P - July 2005
If you need multiple updates to an I/O device during an
TIP
I/O scan, you can enter a logical address in the scan list
more than one time. Do not assign the same partial or full
rack address to more than one channel in scanner mode.
Each channel must scan unique partial and/or full rack
addresses.
Keep these limitations in mind when creating/modifying a
scan list:
The automatic configuration always displays the actual
hardware configuration, except for racks that have their
global-rack inhibit bit set. In this case, the global-rack
bit overrides the automatic configuration. You must
first clear the global-rack inhibit and then select
autoconfigure.
Clear global-rack inhibit bits for the channel that scans
the racks that you want to resume scanning. Use the
scanner mode status screen in your programming
software.
If you change a channel configuration from adapter or
DH+ mode to scanner mode, use the clear list function
of your programming software to clear the scan list. In
any other instance where you need to clear entries from
the scan list, use the delete-from-list function to delete
the entries one at a time.