Rockwell Automation 1756-LSC8XIB8I ControlLogix Low-speed Counter Module - Manual (Page 62)

62 Rockwell Automation Publication 1756-UM536A-EN-P - April 2012
Appendix A Electronic Keying
You can find revision information on the General tab of a module’s Properties
dialog box.
Figure 20 - 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 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.