Rockwell Automation Logix5000 Controllers I/O and Tag Data Programming Manual - Manual (Page 17)

Communicate with I/O modules Chapter 1
• Same catalog number
• Same or higher Major Revision
• Minor Revision as follows:
• If the Major Revision is the same, the Minor Revision must be the same
or higher.
• If the Major Revision is higher, the Minor Revision can be any number.
Disable Keying
Disable Keying indicates the keying attributes are not considered when attempting
to communicate with a device. Other attributes, such as data size and format, are
considered and must be acceptable before I/O communication is established.
With Disable Keying, communication can occur with a device other than the type
specified in the project with unpredictable results. Unpredictable results can
include unwanted and unexpected system behavior.
Be extremely cautious when using Disable Keying; if used incorrectly, this option can lead to personal injury or
death, property damage, or economic loss.
We strongly recommend that you do not use Disable Keying.
If you use Disable Keying, you must take full responsibility for understanding whether the device being used can
fulfill the functional requirements of the application.
More information
For more detailed information on Electronic Keying, see Electronic Keying in
Logix5000 Control Systems Application Technique , publication LOGIX-AT001 .
Rock well Automati on Publication 1756- PM004E -EN-P - October 2014 17