Rockwell Automation 1756-HSC ControlLogix High Speed Counter Module - Manual (Page 74)

Rockwell Automation Publication 1756-UM007C-EN-P - November 2011
74 Configure the 1756-HSC Module
You can find revision information on the General tab of a module’s Properties
dialog box.
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
in order 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 are exactly as specified in the project, such as for use in
highly-regulated industries.
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.