M.T.H. Premier Swiss 6/8 Type II Crocodile Electric Engine Operator's Manual page 35

To do this:
1. Call up the Front engine on your DCC system
2. To set the Front engine to respond to the Bell (F1), Horn (F2), Start-Up/Shut Down
(F3) and Front Coupler (F7) you will want to write a value of 71 to CV21. This is
setting bits 0, 1, 2, and 6 ON.
a. CV21's bits are shown in the table below – the decimal value is shown in
parenthesis:
Bit
(Decimal 7 (128)
Value)
F
F8
Function
6 (64) 5 (32)
F7 F6
Premier Swiss Crocodile Electric Engine
4 (16) 3 (8)
F5 F4
35
2 (4) 1 (2)
F3 F2
0 (1)
F1