Main Ops & Programming Track

I've watched Gregg Berman's series of tutorial videos as I am preparing to build a DCC++/JMRI-based layout. I have a question about the terminology Gregg uses: specifically, what do the terms Main Ops and Programming Track mean?

My assumption is that Main Ops refers to lengths of track wired for power and that Programming Track is wired for changing various settings (e.g. throttle, lighting, sound etc if/as supported by the particular loco being controlled). Is that the correct interpretation of the two terms? If not, I would appreciate some guidance. If I do have it right, is it acceptable to wire the same stretch of track with as Main and Programming Track?

 

There are several ways to describe things, and often the terms are mish-moshed.

DCC can program devices in 2 situations, one is on the "main line" during "operations"... this method uses full track voltage and it sends the address of the decoder being "programmed" so only locos with that address respond. You cannot read back (although some systems have extensions to do something like this).

So this "programming" on the "main" line, during normal "operations" is called POM (programming on the main), or OPs (OPerationS) mode.

The other method is what is called "service mode", and it is only available on a special "programming track", which is normally an isolated piece of track connected to a separate output on your command station/booster. I said normally, sometimes the connections for the wires is different.

But in any case "service mode" or "programming track" uses a much lower voltage to the decoder, and it can read information back. Since only one loco is on this track at a time, you can do things like read the values of settings of a loco, even if you don't know it's DCC address, or short or long address, or other variables.

Greg

 

Greg, Rick - thanks for your replies. I'm working with a rather small layout (2ftx4ft) and will probably have no more than 1-2 locos at a time.

It wasn't obvious to me from Gregg B's videos that either the Main Ops track OR the Programming track can be used for programming (I follow Greg's point that POM supports write but not read) - well, it was obvious that the Programming Track can be used for programming but not that the Main could be too.

Given I have a rather small set up and plan to only use 1 (maybe 2) locos (assuming each loco has a different address), I wonder if I can stick with e.g. wiring up the whole layout as Programming Track from Output +/-B from the Motor Shield (i.e. leave Output +/-A unwired) so that I can read/write no matter where the loco(s) is(are) on the layout? I suppose I could do the opposite i.e. wire entirely for POM (wire with Output +/-A and leave Output +/-B unwired) but would sacrifice the ability to read the loco's settings.

 

I just have a separate short piece of track that isn't even attached to anything as my "programming track". I wire it temporarily to program new locos to set the address and verify other settings. Even with a small layout you will probably end up running a "consist" or MU of multiple locos at once because you can. You can't "run" your layout as the programming outputs. My eventual plan to have a single siding wired with a dpdt switch such that it can be switched between ops mode and programming mode.

 

ADR53 , I had a way larger HO, DCC 'NCE PowerCab' layout than you but only 3-4 total locos. Instead of a separate programming track I used the whole layout for that. It was no biggie to remove the 2-3 other engines while I pulled the engine up to in front of me on the main line. I'd put my PCab in "Ops" mode and do what I wanted with the engine's decoder. If you go this way just be sure the other locos are removed or isolated first. I even blew that a few times over the years. But it's really no biggie either, to reprogram the one you'd left idling on the main..You can not destroy anything while programming; only change CV values. The first thing you'll notice if you did goof up is the other loco's address (usually you'll use the # on side of cab as its address (you will need to understand long and short addresses/piece of cake/Engine 29 or 7 is Diff from 302 or 1506). Finally, 'Prog on the Main' mode does allow you to change a CV value on engine you're running and will not affect other locos. But it's simpler stuff, like, whistle/horn/bell type, momentum, volume, Accel/Decel rate, few others)...It's just another learning curve in your life, and can be confusing. We've all been there /done that. ...M, Los Angeles

 

Thanks very much for sharing your respective insights. Based on all that, I have a plan of action. I'll get to work on that later this week while I'm waiting for my Motor Shield to arrive. At that point, I may resurface with some software-related questions regarding JMRI. In the meantime, thanks again!

 

Same here but my reasoning has to do with my operating system. I am using an MRC Prodigy wireless to run trains mainly because it was what I had but also because I can use my smart phone to operate without going through JMRI. All I need is the MRC wifi module. However, the MRC cannot, according to MRC read TCS decoders and I have a lot of them. So I had to bite the bullet and buy a NCE Power Cab to do my programming.