Program A Decoder For DCC Commands

July 27, 2010

Chuck sent in some thoughts relating to an earlier posting on the blog and comments:

“There was a question as to ‘is a program track necessary’. The response to the question was that signals are sent to the loco via radio signal and an actual program track would not be necessary.

First of all someone needs to understand DCC. A throttle or ‘cab’ as some call it, is either tethered or some work infrared and or radio wave, but the cab sends the commands to the command microprocessor which translates your command into a digital signal that is made for one decoder address. This process is very specific and sent to the decoder hidden in the digital AC power that is supplied the the track by the booster. It is not sent to the decoder via radio.

Now as to the need to a program track. I say yes, you need a program track. Reasons are many but firstly, any programming done on a layout means all decoder on the track that is being used as a programming track will be programmed, if there is only one or more. Secondly, while different systems allow ‘on the fly’ programming where the program is sent to one specific decoder and all the other decoders on the track ignore the new program, because it is sent ‘decoder address specific’, it works well when everything is new and track rails are clean of all oil film, dust, oxidation, good rail joints, distance from booster, size of wire used in the layout, the number of rail-to-power connections, wheel to rail connection (not the best in the real world), need I go on.

In short if you want to program a decoder, why take the chance of the program that is sent through the rail to a decoder, requiring a good connection, with all the variables. It is so much simpler the have a programming track long enough to have the unit being programmed, either connected the your layout, but isolated, through a turn out or separate of the layout. I say take the time and expense of doing it right not trying to cut corners and cause problems and/or grief.

Sorry, I just get so worked up by what is a simple thing and some make it out to be a major project, costing lots of money. At the most, a turnout, two rail isolator joiners, a double pole – double throw micro switch, a couple pieces of track, some wiring and if you want to be fancy a bumper for less then 25 bucks.”

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