Rockwell Automation 1757-FFLDC4 FOUNDATION Fieldbus System User Manual - Manual (Page 99)

Rockwell Automation Publication 1757-UM012A-EN-P - July 2011 99
Create an RSLogix 5000 Software Project Chapter 5
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.
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.