Allen-Bradley Logix5000 Programming Manual

Publication 1756-PM004C-EN-P - October 2009 17
Communicate with I/O Modules Chapter 1
By doing this, you can avoid the case of a physical module rejecting the keying
request because it is an earlier revision than the one configured in the software.
EXAMPLE
In the following scenario, Compatible Keying prevents I/O
communication:
The module configuration is for a 1756-IB16D module with module
revision 3.3. 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 is lower than expected and
may not be compatible w
ith 3.3.
Module Configuration
Vendor = Allen-Bradley
Product Type = Digital Input
Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 3
Physical Module
Vendor = Allen-Bradley
Product Type = Digital Input
Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 2
Communication is prevented

Allen-Bradley Logix5000 Specifications

General

Brand	Allen-Bradley
Model	Logix5000
Category	Controller
Language	English