QUOTE Shunting and half-speed functions:
By defining the different Configuration Variables (#3, 4, 121, 122, 123), a prototypical acceleration and deceleration behavior is achieved that often makes shunting very difficult. With the help of CV #124, a shunting key can be defined (either the dedicated MAN key within a ZIMO system or the keys F4 or F3) with which the acceleration and deceleration rates may be re-duced or eliminated all together. CV #124 may also be used to define either F7 or F3 as low gear key. With this function turned on, the throttle is used for half the decoder's full speed range, which is just like shifting down into low gear.
Example: The F7 key should act as low gear and the F4 key should reduce the momentum down to ¼. According to the CV table, the bits in CV #124 are to be set as follows: Bit 0 = 0, Bit 1 = 1, Bit 2 = 1 and Bit 3 = 1. The sum of the individual bit values (0+2+4+8 = 14) is entered as a decimal value.
CV124 controls Shunting key functions, Momentum reduction or deactivation and Low gear and SUSI assignment.
CV124 can have the following values (0 is the default value) :-
Bit 2 = 0: "MAN" key for shunting, = 1: F4 key for shunting (see Bit 6 for F3 key instead of F4)
Bit 0 = 0: no effect with above key's = 1: removes momentum of CV #121+122
Bit 1 = 0: no effect, = 1: CV #3 + 4 reduced to ¼.
Bit 0 + Bit 1= 0: no effect = 1 removes all momentum above.
Bit 3 = 1: F7 as half speed key
Bit 4 = 1: F3 as half speed key
Bit 5 = 1: For "DC" stopping method *)
Bit 6 = 1: F3 as shunting key (instead of F4 as in Bit 2).
Bit 7 = 1: SUSI deactivated. Solder pads can be used as FO3 and FO4 instead.
*) If "DC" stopping method is used, set CV #29, Bit 2 = 0 and CV #124, Bit 5 = 1 !