What is happening
Functionally, the decoder takes (packets of) data off the track and
uses them to decide what to do: drive a motor, turn on lights,
generate sounds, etc. Let’s look inside and see the basic functions
necessary to make all of this happen.
When I reference colors of wire, I’ll use NMRA recommended
practices wherever they are defined. For the less well defined, I’ll
use industry practices to explain the situation.
There are two basic styles of decoders: wrapped and open boards.
The wrapped units (1) have shrink tubing surrounding the
decoder board with wires coming out of one or both ends.
When I talk about wiring colors in this column, I’ll be referring to
this style of decoder.
Open board decoders (2) don’t have the shrink tubing and fre-
quently have contact points for wiring connections. The con-
nection points are labeled or referenced in the instructions
with this style of decoder.
1: Wrapped decoder example – SoundTraxx Tsunami
TSU-1000.
1
