Rockwell Automation 1794-IP4 Series B FLEX I/O PULSE COUNTER User Manual - Manual (Page 21)

2–5 How to Install Your Pulse Counter Module
Publication 1794ĆUM016B-EN-P - August 2002
Slide the terminal base unit over tight against the adapter.
Make sure the hook on the terminalbase slides under the edge of the
adapter and the flexbus connector is fully retracted.
30077–M
Press down on the terminalbase unit to lock the terminalbase 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.