Rockwell Automation 1756-CFM ControlLogix Configurable Flowmeter Module - Manual (Page 29)

29 Rockwell Automation Publication 1756-UM010B-EN-P - December 2011
Configurable Flowmeter Module Features and Operational Modes 29
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. Release
notes for individual modules indicate the specific compatibility details.
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.
EXAMPLE
In this 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.
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.
Module Configuration
Vendor = Allen-Bradley
Product Type = Digital Input
Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 1
Physical Module
Vendor = Allen-Bradley
Product Type = Digital Input
Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 2
Communication is prevented.