Allen-Bradley CompactLogix 1769-L23E-QB1B Installation Instructions Manual page 31

6. Use the checkbox and pull-down to select your controller and firmware revision.
7. Click Update.
8. Click Yes.
The firmware upgrade begins.
Do not interrupt the firmware upgrade once it has begun.
IMPORTANT
Interrupting the firmware upgrade may result in an inoperable packaged controller.
Rockwell Automation Publication 1769-IN082C-EN-P - February 2013
CompactLogix Controller 31