Allen-Bradley ControlNet Compact GuardLogix 1769, User Manual, Page: 39 / 100

Configure a ControlNet Module Chapter 3
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.
EXAMPLE
In the following scenario, Exact Match keying prevents I/O
communication.
The module configuration is for a 1756-IB16D module with module
revision 3.1. The physical module is a 1756-IB16D module with
module revision 3.2. In this case, communication is prevented because
the Minor Revision of the module does not match precisely.
Module Configuration
Vendor = Allen-Bradley
Product Type = Digital Input
Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 1
Communication is prevented.
Physical Module
Vendor = Allen-Bradley
Product Type = Digital Input
Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 2
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.
Compatible Keying
Compatible Keying indicates that the module determines whether to accept or
reject communication. Different module families, communication adapters, and
module types implement the compatibility check differently based on the family
capabilities and on prior knowledge of compatible products.
Compatible Keying is the default setting. Compatible Keying allows the physical
module to accept the key of the module configured in the software, provided that
the configured module is one the physical module is capable of emulating. The
exact level of emulation required is product and revision specific.
Rockwell Automation Publication CNET- UM001E-EN-P - June 2016 39