Bachmann Online Forum

Discussion Boards => General Discussion => Topic started by: desert_rat on June 13, 2009, 12:35:12 AM

Title: Cannot change address w/Digitrax
Post by: desert_rat on June 13, 2009, 12:35:12 AM
 I have 7 Bachmann Engines. 3 Steam, 4 Diesels.
All but two I could change address. Other two (new) cannot change from #03. One is a Spectrum Item #83313, other Basic Blue box #60602.
Any suggestions ?
Thank You
Title: Re: Cannot change address w/Digitrax
Post by: Guilford Guy on June 13, 2009, 12:44:08 AM
My friend had the same problem, however it was remedied by placing a 1000 ohm resistor across the programming track.
Title: Re: Cannot change address w/Digitrax
Post by: desert_rat on June 13, 2009, 02:04:21 PM
did he just lay (or) attach the resistor across the track while programing? That's what it sounds like.
Thanks for the info.
Title: Re: Cannot change address w/Digitrax
Post by: Guilford Guy on June 13, 2009, 05:44:37 PM
Bob, the DCC system cannot read the CVs, that is why it can't be programmed. I sent my friend an email on where he placed the resistor. Still awaiting a response.

Just Checked Email, and from the sound of it, you place the resistor across the rails, which tricks the zephyr into increasing the output.
Title: Re: Cannot change address w/Digitrax
Post by: Jim Banner on June 13, 2009, 05:50:55 PM
dessert-rat, we have all been assuming that you are using a Digitrax Zephyr command station for your programming.  If that is the case, then the 1000 ohm resistor works.  The important thing is that the wires attached to the ends of the resistor must make good contact with the rails.  If the rails are shinny and bright, and the resistor is new, then laying it across the rails with one wire lead touching each rail will generally do the job.  As the resistor ages, the contact will be less than perfect and so will your results.  Adding an alligator clip to each of the lead wires, either by soldering or by using clips with screws, will give you a handy jig that is easy to put on and take off and will work every time.   You can even go one step further and use a small switch to connect it to/disconnect it from your programming track.

If necessary, you can program blind, that is, without reading the present values of CVs.  At least with the Zephyr you can.  I am not sure about the Digitrax DCS100 command station used in the Super Chief set.  But blind programming can be tricky as you have to hit all the right buttons in the right order or you end up who knows where.  Some command stations program CVs only this way.  This includes the Digitrax DB150 command station used in the Super Empire Builder set.  Blind programming (also know as P'n'P or Push and Pray programming)  led to the invention of reset to factory defaults so you could start all over again from a know set of CVs.

If the command station you are using is not a Zephyr, then the problem probably lies elsewhere.  If the two locomotives that you are having problems with do not have their original Bachmann (Lenz) decoders then the problem lies elsewhere.  So if you still need help, let us know what decoder (if not factory installed), which Digitrax command station and what address you are trying to program in.  Some command stations handle addresses between 100 and 127 differently than others.  Some command stations require resetting CV29 for certain address changes while others do not.  Digitrax throttles before the DT400 handled 4 digit addresses differently than the later throttles. And some decoders have a lock feature that stops the decoder from accepting any programming until it is turned off.  So you can see why we need your help in order to help you.

Jim
Title: Re: Cannot change address w/Digitrax
Post by: desert_rat on June 14, 2009, 12:03:50 PM
 More info.
Brand new Zephyr, new track (but will go the attached clip route).
Tried the blind route, nothing happened.
Had the Distributor for Digitrax come over and try, no success.
Will Visit Radio Shack and buy 100 ohm resistor tomorrow (if not today).
Just didn't want to burn anything up before asking.

Thanks everyone.
Title: Re: Cannot change address w/Digitrax
Post by: Guilford Guy on June 14, 2009, 12:06:15 PM
Quote from: desert_rat on June 14, 2009, 12:03:50 PM
More info.
Brand new Zephyr, new track (but will go the attached clip route).
Tried the blind route, nothing happened.
Had the Distributor for Digitrax come over and try, no success.
Will Visit Radio Shack and buy 100 ohm resistor tomorrow (if not today).
Just didn't want to burn anything up before asking.

Thanks everyone.
Just to clarify its a 1000 ohm, not a 100 ohm resistor. Unsure if that was a typo.
Title: Re: Cannot change address w/Digitrax
Post by: desert_rat on June 14, 2009, 06:26:57 PM
 Correct, "1,000 ohm". (Typo)
Will advise tomorrow night.
Thanks again.
Title: Re: Cannot change address w/Digitrax
Post by: WGL on June 15, 2009, 02:30:27 AM
 I have a Digitrax Zephyr.  I was unable to get the resistor to work by laying it across the track.  Tonight, I laid it across the track under the fuel tank of my Spectrum SD45, & it worked.  I laid it under the wheels of my Spectrum 2-10-2's tender, & that worked.

I found that CVs 3 & 4 in both Bachmanns were set at the factory to 001. Since the Digitrax decoders I installed into my BLI locos had CVs 3 & 4 set to 000, I confirmed that Spectrum DCC onboard comes with momentum, while the decoders I installed had no momentum set.
Title: Re: Cannot change address w/Digitrax
Post by: Jim Banner on June 15, 2009, 10:24:46 AM
WGL, sounds like it's time to add a couple of alligator clips as I suggested in my previous post on this thread.  It saves a lot of frustration.

Jim
Title: Re: Cannot change address w/Digitrax
Post by: desert_rat on June 16, 2009, 08:30:53 PM
IT WORKS ! That's all I have to say other than

Thank You All.
Title: Re: Cannot change address w/Digitrax
Post by: Guilford Guy on June 16, 2009, 10:12:49 PM
Quote from: desert_rat on June 16, 2009, 08:30:53 PM
IT WORKS ! That's all I have to say other than

Thank You All.
Your Welcome!
It was quite an accomplishment when we got the 2 GP35s running over the pass.
Good luck to you on your railroad.
Title: Re: Cannot change address w/Digitrax
Post by: Jim Banner on June 16, 2009, 10:40:47 PM
TWO THUMBS UP!!

Jim
Title: Re: Cannot change address w/Digitrax
Post by: Jim Banner on June 18, 2009, 09:37:02 PM
Five wires?  My suggestion was to put an alligator clip on each end of the resistor so that you could clamp it firmly on the rails.  Yampa Bob has posted a nice photo at the link below:

http://tinyurl.com/kl7y4l (http://tinyurl.com/kl7y4l)

Unfortunately, the link above and Bob's link below are to a thread which seems to have been deleted.  JB 21 August 2009

Jim
Title: Re: Cannot change address w/Digitrax
Post by: Yampa Bob on June 18, 2009, 10:30:04 PM
Thanks Jim,

Have you ever determined the approximate total equivalent resistance of the loco / decoder on the program track?

Members of some discussion groups have reported using anywhere from 22 ohms and upward to do the job. A few even reported successfully programming Soundtraxx decoders without the PTB-100 booster.

For inquisitive minds that want to know what the heck we're talking about.

http://www.electronics-tutorials.ws/resistor/res_4.html

Thanks 



(Test)
http://www.bachmanntrains.com/home-usa/board/index.php/topic,9599.0.html

Jim,
I posted the full URL to my thread above. The hyphen makes it break even in IE, so apparently no need to "tiny" forum topic URLs. I am surprised that today's webmasters don't realize spaces create the dreaded %20 fillers.

I liked your idea of a switch for the resistor for frequent use. I just showed the basic concept. I have an ancient resistor/capacitor substitution box, gosh I can't even remember when I got it but glad I didn't sell it.
Title: Re: Cannot change address w/Digitrax
Post by: pdlethbridge on June 18, 2009, 10:34:02 PM
there goes another headache :'( :'( :'( :'( :'( :'( :'(
Title: Re: Cannot change address w/Digitrax
Post by: Yampa Bob on June 18, 2009, 10:56:39 PM
Paul,
Consider yourself lucky...I could have wrote "the reciprocal of the sum of the reciprocals of the individual resistors,  or the product of 2 resistors divided by the sum". I started to but I know you prefer pretty pictures.   8)
Title: Re: Cannot change address w/Digitrax
Post by: Jim Banner on June 19, 2009, 12:55:07 AM
No, I haven't measured the resistance looking into a decoder from the rails.  I suppose the key resistance would be right at the point where the decoder applies power to the motor to acknowledge the CV update.  As far as minimum resistance is concerned, there would be two values - one below which the acknowledge pulse would be too low to read the other below which the programming circuit would be damaged.  For the Zephyr (DCS50) and the Super Chief (DCS100) the latter resistance would be zero.  The programming circuits are protected against short circuits.  They are not, however, protected against other current sources, such as the running track.

I have had no problems so far programming a Tsunami TSU-1000 with my Zephyr running barefoot.  Or with reading it back.  I don't know if Soundtraxx has made some changes or if the first batch of Zephyrs was more sensitive reading back.  All I can say at this point is that so far it works.  Same with the large scale QSI decoder, another nice noise maker.  The manuals are a bit of a killer.  Between the user manual and the technical reference manual, it was something like 270 pages.  The Tsunami is not quite as bad at about 150 pages.  No wonder people are installing these things and changing nothing but the address.

Jim

p.s. for those born in the latter half of the last century, "running barefoot" is a CB radio term meaning "running without a booster."  Some CB operators ran "a full gallon" which was a one kilowatt booster, a whole lot more power than the legal maximum of 3 or 5 watts.  With that much power, you could drown out everybody within a ten mile radius.  I got a bigger kick out of "working skip" (bouncing signals off the ionosphere) from northern Alberta down to Texas and Louisiana (about 2000 miles) with a 3 watt mobile rig.
J


Title: Re: Cannot change address w/Digitrax
Post by: WGL on June 19, 2009, 02:20:02 AM
 Thanks Bob & Jim!  All is clear to me now.
Title: Re: Cannot change address w/Digitrax
Post by: Union Jack on June 23, 2009, 07:26:58 PM
Recently acquired the 44 ton switcher w/DCC and could not change address with my Digitrax system.  I found this thread, picked up a 1000 ohm resistor, took the advice regarding alligator clips and walla I'm a happy camper.  THANX much!