Rockwell Automation 1794-ID2 U.MNL INCREMENTAL ENCODER - Manual (Page 27)

2–5 How to Install Your Incremental Encoder Module
Publication 1794ĆUM015B-EN-P - May 2001
Slide the terminal base unit over tight against the adapter.
Make sure the hook on the terminal base slides under the edge of the
adapter and the flexbus connector is fully retracted.
30077–M
Press down on the terminal base unit to lock the terminal base on the
DIN rail. If the terminal base does not lock into place, use a screwdriver
or similar device to open the locking tab, press down on the terminal
base until flush with the DIN rail and release the locking tab to lock the
base in place.
Gently push the flexbus connector into the side
of the adapter to complete the backplane connection.