Rockwell Automation 5720 DriveLogix System - Manual (Page 94)

Publication 20D-UM002C-EN-P - November 2003
4-10 Placing and Configuring Local I/O
communication format: rack optimization (which corresponds to a rack-optimized connection for the I/O module)
The rack-optimized tags are created as aliases into the array tag Local:I, which
is the array for input modules on the local rail. This array contains one element
for each slot on the rail (based on the chassis size you specify when you
configure the rail). You can either address the rack-optimized module by the
alias tag (which uses the slot number) or the array element in the rail tag. If you
enter the alias tag in your logic, the programming software displays the base
tag.
Local:I contains an element for each possible slot on the rail, whether you
actually install an input module there or not. Local:O also contains an element
for each possible slot. If you configure a module on the local rail as a direct
connection, do not use the associated array element in Local:I or Local:O. Use
the tag the software creates for the module (which uses the slot number).
Inhibiting I/O Module
Operation In some situations, such as when initially commissioning a system, it is useful
to disable portions of a control system and enable them as you wire up the
control system. The controller lets you inhibit individual modules or groups of
modules, which prevents the controller from trying to communicate with the
modules. Inhibiting a module shuts down the connection from the controller
to that module.