DCC tech question for the experts.

[grandeman]

Our new Digitrax system is working very well. One problem though, we can't get any of our old MRC AD310 decoders to respond. I've tried every 14 speed step CV29 in our books. The system runs Digitrax equipped locos perfectly and the old decoders were working on the old MRC system. I know these are "junk" decoders, but it would be nice if we could use them until we get around to replacing them. Some are hard wired into IHC staemers, aaarrrhhh! Any ideas? Thanks!

[cjcrescent]

Eric;
If you still have the instructions on the MRC decoders, see if you can do a factory reset on the decoder and then attempt to reprogram the address.
Not being familiar with MRC, other than trying this, I'm at a loss otherwise.

[Pennsy58]

One issue I am aware of with this series of decoders is that they cannot accept a two digit address through normal address programming. I also believe there is a workaround for doing the address but I cant find my notes at the moment. I know this doesnt solve your problem but it may give you a direction to explore.

[grandeman]

Thanks guys.

Carey, the MRC "instructions" are next to worthless. I've got an email in to the tech dept at Digitrax but may give them a ring tomorrow. Let me know when you want to come over. We'll run some trains.

[simon1966]

Grande Man, consider joining the Digitrax Yahoo Group. http://groups.yahoo.com/group/Digitrax/ with some 5000 odd members, it is a very valuable resource for Digitrax products. I have posted several questions over the past year and usually get an answer in minutes. There arn't many things that have not been seen before.

[rrinker]

To program them you have to use register mode -they only support a limited set of CV's. The display as you toggle through programming modes will say Pr I believe (I don't do much programming from my DT400, I have the computer hooked up and use DecoderPro). If they were working on your old MRC system, they should haev addresses like 1, 2, 3, etc depending on which throttle you programmed them for - at least that's my understanding of how the older MRC systems work - Prodigy Advanced is the first MRC system to use 'normal' addressing. To run them - you have to Status Edit the decoder address for 14 steps - Section 17 in the manual. Press Loco, key in the address, press EDIT until the display says STAT 14, and then hit ENTER. Give that a try, see how that works.

--Randy

[grandeman]

QUOTE: Originally posted by rrinker

To program them you have to use register mode -they only support a limited set of CV's. The display as you toggle through programming modes will say Pr I believe (I don't do much programming from my DT400, I have the computer hooked up and use DecoderPro). If they were working on your old MRC system, they should haev addresses like 1, 2, 3, etc depending on which throttle you programmed them for - at least that's my understanding of how the older MRC systems work - Prodigy Advanced is the first MRC system to use 'normal' addressing. To run them - you have to Status Edit the decoder address for 14 steps - Section 17 in the manual. Press Loco, key in the address, press EDIT until the display says STAT 14, and then hit ENTER. Give that a try, see how that works.

--Randy

Whoa!!! I tried this and it did get the engine running but it was uncontrollable. Full stop wasn't at the zero position on the throttle and movement of the knob in either direction resulted in full speed, in opposite directions! Then, in trying to fine tune it, the system made a rapid chirping sound and continued until we pulled the power cord. Nothing else would shut it off. When we powered back up, all consisting was lost. Unless Digitrax tech support has an easy solution, that's the last MRC decoder that will ever be used on the layout . Randy, you're right about the way to go about this (register mode, stat 14) but I'm afraid to try it again.

[rrinker]

Try one you haven't messed with, that you know the address of, and see if it just runs when you status edit to 14 steps. What's wierd is how it took off even if you turned the knob counter-clockwise - because once it's at 0, you can crank it all day and it won't change.

--Randy

[JohnT14808]

Wow....good thing you didn't crash into anything. Sounds almost like in your earlier efforts you may have programmed a "full speed" code into some CV without realizing it. Is there any way to do a factory reset?

[grandeman]

QUOTE: Originally posted by JohnT14808

Wow....good thing you didn't crash into anything. Sounds almost like in your earlier efforts you may have programmed a "full speed" code into some CV without realizing it. Is there any way to do a factory reset?

I think the MRC decoders may get a "grande man" throw away instead. [:D]

[grandeman]

QUOTE: Originally posted by simon1966

Grande Man, consider joining the Digitrax Yahoo Group. http://groups.yahoo.com/group/Digitrax/ with some 5000 odd members, it is a very valuable resource for Digitrax products. I have posted several questions over the past year and usually get an answer in minutes. There arn't many things that have not been seen before.

Thanks Simon. I'll be spending some time there.[;)]

[rrinker]

I don't think those old MRC decoders HAVE a reset option. But then they only support about 5 CVs so it's not too hard to just reset them all. It could be that the start voltage got set to some large number, which would explain high speed operation at speed step 1.
The issue of the MRC decoders (and old Lenz decoders as well) that support only register mode comes up frequently on the various DCC lists, so a search of any of them should turn up the programming directions as to what CV corresponds to what register.

--Randy

[Anonymous]

You might try the Atlas forum - DCC group as well they cover all DCC not just Atlas. The more experts the better! Good luck, and hope that there is an easy solution out there!
Will

[grandeman]

Hi All. After joining the Yahoo group I got an answer. Randy is right about Register mode being the only way to do it. A fellow named Don Crano gave a very detailed post on the old MRC decoders. It took some serious "fiddling" but I managed to get them programmed and the addresses set up for 28 speed step functioning (MRC decoders only). They're all running as good as old 28 SS MRC decoders are capable of...

BTW, last night I was trying to program on the main, a serious no no. [:I] No serious melt downs occured on the program track I just set up.