Rockwell Automation 1756-XXXX ControlLogix Digital I/O Modules - Manual (Page 41)

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 41
Common Module Features Chapter 3
Electronic keying is based on a set of attributes unique to each product revision.
When a Logix5000 controller begins communicating with a module, this set of
keying attributes is considered.
You can find revision information on the General tab of a module’s Properties
dialog box.
Figure 8 - 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.
Attribute Description
Vendor The manufacturer of the module, for example, Allen-Bradley.
Product Type The general type of the module, for example, communication adapter, AC drive, or digital I/O.
Product Code The specific type of module, generally represented by its catalog number, such as 1756-IB16I.
Major Revision A number that represents the functional capabilities and data exchange formats of the
module. Typically, a later major revision supports at least all of the data formats supported by
an earlier major revision of the same catalog number.
Minor Revision A number that indicates the module’s specific firmware revision. Minor revisions typically do
not impact data compatibility but may indicate performance or behavior improvement.
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