I have an older digitrax EB unit that has no provision for a program track. Called Digitrax about how to go about adding one. Told me I didn’t have one & that was that, wouldn’t give any more information. It seems to me it’s only a separate feeder line with a current limiting resistor in it. Probably keeps you from smoking the decoder. I’ve installed about 14 decoders without the program track & only smoked 1. Three questions.1 Do I need one. 2 do I only need to install a resistor in the line to an isolated track? 3 What value should the resistor be? Thanks
While programming tracks are wonderful things, they are certainly not required, especially not with an Empire Builder as it will not read back CV values anyway. Use OPS mode programming on the mainline. This works excellent and is supported by all the recent decoder releases.
Jeff
Thanks Jeff. I wasn’t really concerned about reading CVS…but that would be nice. More interested in not burning up the decoder while programing.
Programming tracks are nice to avoid runaway locomotives. I’ve droppeed a BLI locomotive out of the box onto my DCC layout and it took off at full speed. Luckily I could grab it in time. I use a DPDT switch to switch a section between normal DCC and programming. Works fine.
Thanks, I guess the real question is, Does the programing track lower the amperage ? If so what value is needed. I Quess I would have to drop it lower than the rating of a decoder… .5 amps or so
Jerry,
Maybe I misunderstood your original question but a programming track will not help you much in the case of a mis-wired decoder. While the life of the decoder may be extended for a second or two, it’s not going to offer you the kind of protection it sounds like you are after. Keep in mind that dropping the voltage to the rails seems to be a good idea and would work to some extent, but a short is still a short and once the tolerances of the decoder are exceeded it will go bye bye.
My suggestion would be to be more careful during your installations and do a very good job of inspecting things before applying power to the locomotive. Having only lost one decoder in the first fourteen means that you are doing a pretty good job of this already (I blew up several more than that in the first twenty I did if memory serves… [;)]
Jeff
I don’t know if the programming track has a lower amperage output. I’ve never looked. You could do he lightbulb in series trick which will limit the current in case of a short. A resistor can work too but lightbulb have dynamic resistance, which keeps them from heating up unless the current rises above a certain point.
I built a programming track to keep from making night-ruining D’OH’s.
As you can see, it need not be more than 2’ long, and requires feeders between your controller and each rail. In the case of my SEB, I remove the layout bus wires from their sockets, and merely place the twin feeders from the programming diorama into those same sockets. Then I program in the new loco’s new address. That is all I use it for. All other CV modifications can be made in Ops mode right on the main, even with a mix of other decoders on the layout doing their things concurrently. Fortunately, if you programme in Page Mode inadvertently with the SEB, while on the main, it shuts down the power to the track, and you must dial in each loco to get it to come back for you. A bit unnerving, but I have had this experience consistently…when I make the goof, of course. Hasn’t happened recently.
I get no readback of CVs in Ops Mode with my DB150, but it will show the last setting if I keep exiting, trying the function, and then re-entering into Ops Mode to make another adjustment. If I turn the encoder one click (only) clockwise, it will show my last value plus one.
I read the DT400 manual, and it says that it will readback CV values in Page Mode. I’ll have to check that out next time I can run my trains…in two weeks if all goes well.
-Crandell
Edit - I reread the DT400 manual, and it says that CV readback is not possible with the DB150. Darn.
I will check my programming track volts and amps the next time I get to run trains. The DCS-100 booster has the separate outputs for the programming track. I find the programming track handy to make CV modifications at my round house and work bench. I use a DPDT switch to swap between run and program witha center off position.
If I recall correctly, the other purpose of a programming section (or track) is to isolate one decoder from the others to prevent an accidental “oops, now my locos are address x!” global CV change.
The programming track has saved me a couple of times from runaway locomotives. I’ve had BLIs right out of the box that when dropped onto a normal DCC track would instantly take off and I’d have to grab them before damage occurs. I use a DPDT switch on a siding and make it a programming track when needed. No more run aways.
How you wire the programming track depends on your system. With a sysem like the Super Empire Builder that doesn;t have a seperate program track connection, you isolate a siding with gaps in both rails, and wire a switch to cut power to the rest of the railroad. Both wires - so use a DPST or DPDT switch. I believe there is a picture on the Digitrax site.
For a Zephyr or Super Chief, or any system that has a program track connection, the DPDT switch gets connected to the isolated siding (or it can be a piece of track not connected to the layout at all - in which case no switch is needed). The CENTER terminals go to the track. One side goes to the track output on the command station, the other goes to the program track output. Throw the switch one way, the track is a program track, throw it the other way, it’s a regular track you can run locos on. That’s what I did, with a siding that runs right near the front of my layout. I can drive the loco in, throw the switch, and program.
–Randy
RANDY, yes, that’s what I’m doing now. I used to run with a block sys. I use one siding as a “program” track, switching all other blocks off. I thought I read somewhere that the program track also limited either voltage or current. This is the aspect I’m interested in.
It is on those systems with a dedicated program track connection - no need to install anything else. And I’m pretty sure it is even on the DB150 when in program mode, the key being that you would have to be in program mode before placing the loco on the track, otherwise it will see full track power.
–Randy
Randy, I am going to try that (going into programming mode before setting engines on the programming track) but the last three BLI’s I’ve bought took off when droppeed onto a normal DCC track without the decoder being programmed. Seems odd they would come out of the factory that way. If I flip the DPDT switch to connect them to the DB150 programming track outputs, program the decoder and then flip it back to normal DCC, it works fine. Maybe it’s a QSI thing. Any locomotive I’ve upgraded to DCC with a Digitrax decoder hasn’t done this but I don’t recall the Atlas *-40CWs doing this and they are QSI. I’ll assume it is a BLI thing.
I think those engins come with a DC /DCC decoder, it may have "thought ‘’ 'it was on DC. Thats why you should deactivate the DC ability on all decoders. They run lousy on DC anyway
Another solution??? Get a Locobuffer USB and download the FREE DecoderPro software from JMRI. It makes programming a breeze. No computer near your railroad? I have a few pieces of track, one with a railer) glued to a length of 1 x 4, that I connect to the SEB with alligator clips on the leads. So I can take it to my computer. jc5729
I’ve burnt up two decoders trying to install a Bachmann decoder in a Bachmann 0-6-0 switcher. The area is so tight that, I’m not sure that I have’t created a problem when I put the body on. The first one ran for one hour than SMOKED it, I got better on the second on it lasted only 10 minutes. This locomotive was sold as DCC ready. But could it be drawing too much current? Any help out there?
DCC systems that have programming track outputs have an internal 10 Ohm power resistor on the output to protect the system and mis-wired decoders.