Rockwell Automation 1769-ASCII Compact I/O ASCII Module - Manual (Page 110)

110 Rockwell Automation Publication 1769-UM012B-EN-P - January 2014
Appendix E Using Electronic Keying
If you use Disabled Keying, you must take full responsibility for understanding
whether the module being used can fulfill the functional requirements of the
application.
EXAMPLE In the following scenario, Disable Keying prevents I/O communication.
The module configuration is for a 1756-IA16 digital input module. The physical
module is a 1756-IF16 analog input module. In this case, communication is
prevented because the analog module rejects the data formats that
the digital module configuration requests.
Module Configuration
Vendor = Allen-Bradley
Product Type = Digital Input Module
Catalog Number = 1756-IA16
Major Revision = 3
Minor Revision = 1
Physical Module
Vendor = Allen-Bradley
Product Type = Analog Input Module
Catalog Number = 1756-IF16
Major Revision = 3
Minor Revision = 2
Communication is prevented.