Rockwell Automation 1756-XXXX ControlLogix Digital I/O Modules - Manual (Page 45)

Rockwell Automation Publication 1756-UM058G-EN-P - November 2012 45
Common Module Features Chapter 3
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.
EXAMPLE In the following scenario, Disable Keying allows I/O communication:
The module configuration is for a 1756-IA16 digital input module. The physical
module is a 1756-IB16 digital input module. In this case, communication is
allowed because the two digital modules share common data formats.
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
Module Configuration
Vendor = Allen-Bradley
Product Type = Digital Input Module
Catalog Number = 1756-IA16
Major Revision = 2
Minor Revision = 1
Physical Module
Vendor = Allen-Bradley
Product Type = Digital Input Module
Catalog Number = 1756-IB16
Major Revision = 3
Minor Revision = 2
Communication is allowed