lr, I don't think you can "trigger" the "Small Scale" sounds with the RCS triggers, if I understand correctly those are done with voltage or sensor pickup...I really like the sound (I've heard online) and the report from others as well!
from the SS website...quote as follows....
DO YOU NEED DCC OR SPECIAL CONTROLS?
No. The Mini-Prototype Sound Unit's tiny computer does all the work. It is designed for "hands free",
user friendly, automatic operation. Some sound units on the market require you to hold down a button
while applying power in a particular (sometimes frustrating) pattern to get the unit to make sound, or
some units may require you to have DCC or a large investment in some other controls to make theirs
operate. Some sound systems look like you need an advanced college degree to operate them.
HOW DO YOU CONTROL THE BELLS?
To save cost, space, ease installation requirements and make the operation of the units as easy as
possible...almost all the Mini-Prototype Sound Units have the following control strategy programmed
into them (steam engine example, diesel is similar):
At the first detection of movement one of the following combinations may be given...
1) Safe to Proceed Whistle/Horn followed by the bell with semi-synchronized chuffs
2) Safe to Proceed Whistle/Horn followed by speed synchronized chuffs
3) Safe to Proceed Whistle/Horn followed by the drain cock purges before speed synchronized chuffs
4) drain cock purges before speed synchronized chuffs
5) bell with semi-synchronized chuffs
6) synchronized chuffs
Once the engine is going fast enough, or after 60 seconds, the Bell sound will be disabled until the
engine stops. When the engine is stopped, the tiny computer will change to the next combination in
the listing above after 30 seconds. Some engines perform only some of the above combinations.