Rockwell Automation 9904-RPFM ControlNet Modular Repeater Medium-distance Fiber Module Installation Instructio - Manual (Page 6)

6 ControlNet Modular Repeater Medium Distance Fiber Module
Publication 9904-IN011A-EN-P - October 2000
3. Press the module down onto the DIN rail until flush.
The locking tab should snap into position and lock
the module to the DIN rail.
4. If the module does not snap into position, use a screwdriver or similar
device to move the locking tab down while pressing the module flush onto
the DIN rail. Release the locking tab to lock the module in place. If
necessary, push up on the locking tab to lock.