Rockwell Automation 1756-IH16ISOE ControlLogix Sequence of Events Module - Manual (Page 65)

Publication 1756-UM528A-EN-P - April 2004
Using the Sequence of Events Module Features 5-13
Electronic Keying
Instead of plastic mechanical backplane keys, electronic keying
allows the ControlLogix system to control what modules belong in
the various slots of a configured system.
During module configuration, you must choose one of the
following keying options for your Sequence of Events module:
• Exact Match
• Compatible Module
• Disable Keying
When the controller attempts to connect to and configure a
Sequence of Events module (e.g. after program download), the
module compares the following parameters before allowing the
connection and configuration to be accepted:
• Vendor
• Product Type
• Product Code
• Major Revision - Change that affects the module’s function or
RSLogix 5000 interface
• Minor Revision - Change that does not affect the module’s
intended function or RSLogix 5000 interface
The comparison is made between the keying information present
in the module and the keying information in the controller’s
program, preventing the inadvertent operation of a system with the
wrong module in the wrong slot. For example, if you select Exact
Match and a module with revision 1.2 is placed in a location
configured for a module with revision 1.4, the controller does not
make a connection to the new module because of the mismatched
revisions.