Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 38)

38 Publication 1756-UM009C-EN-P - December 2010
Chapter 3 ControlLogix Analog I/O Module Features
General Tab
Exact Match
Exact Match Keying requires all keying attributes, that is, Vendor, Product
Type, Product Code (catalog number), Major Revision, and Minor Revision, of
the physical module and the module created in the software to match precisely
to establish communication. If any attribute does not match precisely, I/O
communication is not permitted with the module or with modules connected
through it, as in the case of a communication module.
Use Exact Match keying when you need the system to verify that the module
revisions in use are exactly as specified in the project, such as for use in
highly-regulated industries. Exact Match keying is also necessary to enable
Automatic Firmware Update for the module via the Firmware Supervisor
feature from a Logix5000 controller.
IMPORTANT
Changing electronic keying selections online may cause the I/O
communication connection to the module to be disrupted and
may result in a loss of data.