Programming track

[Andy Parkinson]

I'm a newcomer to DCC and my new layout is an end to end which will only have one loco or two in tandem working together at any one time. With an NCE system is there an absolute need for a programming track or can each loco be programmed on the layout and then physically removed and the next one done & so forth? Just wanted to avoid further wiring if possible and with only a few locos to operate wondered whether a programming track was absolutely necessary.

Thanks,

Andy

[Nigelcliffe]

It will work correctly as you propose.  

But, you must have only one decoder on the layout at a time for programming, and that includes any accessory (turnout) decoders should you choose to use DCC controlled turnouts or signals.

 

 

- Nigel

[Danemouth]

Any additional locos remaining on the layout get reprogrammed at the same time as I discovered to my cost. Danemouth Mk 2 has one siding at the front of the layout set up as a programming track - would not now wish to be without it.

 

Dave

[richard brown]

Why not put a programming track out of the way from you layout or if you are using point countrol next them or even hzve a connector so you plug it in when you need it.

[HLT 0109]

It will work correctly as you propose.  

But, you must have only one decoder on the layout at a time for programming, and that includes any accessory (turnout) decoders should you choose to use DCC controlled turnouts or signals.

 

 

- Nigel

I do not think this is the whole story.  I believe it is correct if you wish to programme an address into a loco but NCE Powercab permits "Programming on Main" whereby one first identifies the loco address and can then alter other  CVs.  However, you cannot read CVs on main which is a good reason for having a short programming track.

 

Harold

[corax67]

It's not a necessity but it is a nicety.

 

I always fit a length of flexi-track onto a fiddle yard as a programming track having seen a layout full of loco's reprogrammed at the same time in error many years ago.

 

Costs nothing but saves a whole heap of heartache in the long run.

[Dunmar]

Hi,

I have an end to end exhibition layout and have fitted track to a short piece of wood no bigger than that of a loco! I have heard of so many disasters involving programming on the 'Main' that I would never consider it any other way.

Bill.

[Alcanman]

I do not think this is the whole story.  I believe it is correct if you wish to programme an address into a loco but NCE Powercab permits "Programming on Main" whereby one first identifies the loco address and can then alter other  CVs.  However, you cannot read CVs on main which is a good reason for having a short programming track.

 

Harold

This is correct. I also use an NCE Powercab on my small layout which usually only has 1 or 2 locos on at a time.  However, there is no need to for a seperate programming track as you can simply switch from 'programming on the main' to 'program track' mode with the handset. 'Programming on the main' is particularly useful for adjusting sound volume as the sound is cut off in 'program track' mode due to reduced voltage.

 

As others have stated, if you can find space for a piece of track and manage the extra wiring then this is 'best practice' and will avoid errors.

 

Mal

[philsandy]

My fiddle yard consists of a very short (21") 3 track traverser, would that serve as a programming track?

[Izzy]

My fiddle yard consists of a very short (21") 3 track traverser, would that serve as a programming track?

 

 

I do think, as a relative newcomer to DCC who continues to learn all the time, that the difference between programming in program mode on a program track and 'on the main' needs to be fully understood to appreciate not only the differences, but the dangers.

 

Program mode has the benefit of working at minimal power output, so in case of any problems, the chances of damaging a decoder are greatly reduced. It at it's most useful for initial testing of a newly fitted loco where the wiring/connections needs checking/confirming, and of course reading CV's. I soon learnt that it is best to use a completely separate piece of track so that no danger exists of a loco breaching any joint between a track with program mode and the main DCC track output mode, because otherwise the command station program mode outputs will be blown, (guess how I discovered this?). For this reason I would not reccomend using any track in program mode where there is a possibility that this could occur, as even though a DCC system is put into program mode output, it does not always follow that the full mode outputs are switched off, as some systems have separate wiring outputs for each mode.

 

Izzy

[Oldddudders]

If used properly - i.e. read your manufacturer's instructions and follow them to the letter - Ops Mode Programming/Programming on the Main holds no terrors at all. My layout (Digitrax), which sees little running, has about 20 locos lying about on it, most of which have been there for 5 or 6 years. I regularly bring the latest purchase in and programme it on the main. I have never, ever, managed to re-programme everything else, which the cynics say is an inevitable consequence.

[pauliebanger]

POM is not the potential problem being described, I believe, but the way the OP's system, NCE PowerCab handles the two methods. Some Roco and Digitrax have similar 'features'.

 

The PowerCab uses one output pair of wires only. No dedicated Programme Track supply.These are switched between normal and programming tracks. Unless there is a dedicated (ie isolated) section, the whole of the (connected) layout becomes one enormous programming track if Service Mode is enabled. Since Service mode programming does not require the loco ID to begin the process, any loco on the tracks could potentially be unintentionally reprogrammed. Since any such event would be unintentional, erratic behaviour might later be observed, but no immediate cause be identified. 

 

The simple and convenient way in which the PowerCab can put into service mode programming, to read a current CV for instance, is the very thing which is likely to lead to such a mistake.

 

I would, therefore, support the view that not only should you use a dedicated programming track for the times when POM is not appropriate, but that you protect the rest of your system either by completely isolating the programming track, or fitting the NCE add-on Auto Switch to switch off track power to the rest of the system whilst you are in service mode programming. http://www.digitrains.co.uk/ecommerce/search/auto-sw.aspx and here http://www.tonystrains.com/technews/nce_aswitch_review.htm

 

 

You could always use a DPDT switch to achieve the same result for less money, but that is not automatic and therefore not failsafe. Even experienced operators can make mistakes. It's the owner's choice, of course, but for me the value of the 'back-up' is worth far more than the few quid it will cost.

 

Paul

[HLT 0109]

I agree with you entirely Paul, and I have a short, isolated siding that is my programming track.  As I said earlier, it is the only place with Powercab that one can read CVs as well as write them but here are times when it is necessary to 'program on main' - for example when speed matching locos.  That would be impossible on a short programming track so it is necessary to use the rest of the  layout - then, as you say, care is needed to ensure the 'use programming track' is NOT selected!

 

Harold.

[HillsideDepot]

I have a number of layouts which share a Lenz unit, so I have fitted the base station with a simple plug arrangement which I then connect into the socket on which ever layout is set up at the time. Then, on a shelf above my workbench there is a rolling road set-up and with a similar socket arrangement so I can connect the DCC unit to the rolling road. I can also connect a DC supply to the rollers, so a new loco can be run in first on DC, then I swap to the DCC controller (I can only plug in one or the other at a time) and having fitted the chip I can programme the loco, either on the rollers or the adjacent length of track.

 

Slightly more complex, but it works for me.

[Glynn Huggins]

In a small fiddle yard, you could always fit a  D.P.D.T. switch to switch between ordinary DCC power and programming track power to the siding thus getting the best of both worlds. The switch will have six connections; the middle two being for +ve and -ve power to the siding and the other two pairs for +ve and -ve input from the power unit (assuming there are two separate outputs such as on the elink, one for DCC and one for programming.)

This works for me.

Glynn

[Ron Ron Ron]

Here are some ideas for wiring up a programming track which is incorporated into and part of a layout (siding etc,).

 

http://www.brian-lambert.co.uk/DCC.html#Programming

[ColinK]

On my layout, one road in the goods yard is isolated from the rest of the track using isolating fishplates. It is then fed power from a DPDT switch, one side of the switch is fed from the 'normal' track power, the other side is fed from the programming track output from the controller. So to programme a loco, i shunt it into the siding, move the switch to programme; it works for me.

 

I've made the programming siding long enough for a 2 car DMU s I can programme both cars at once.

[Passed Driver]

Hi All. I have seen a YouTube video ( or two) on wiring a programme track using a DPDT centre off toggle switch , and I followed this idea. And it has been claimed that testing a Decoder wired Loco on the programme track first

My question is "How is this track less likely to cause a Decoder to fry " as the same power is going to both sets of contacts.

Kevin

[RAF96]

When programming in Service Mode the NMRA standards and recommended practices require a limited 200mA current specifically to protect a decoder against damage due to miswiring.

 

When POM the decoder gets full track current up to the limit of your PSU/controller/other protection circuit and hence the chance of any undetected dodgy wiring (even DCC ready locos can have wiring faults ex-factory) destroying your decoder.

 

I use a rolling road as my test track and programming track by way of a DPDT switch as my controller has separate Track and Prog outputs but the single output controller feed can be wired up the same except the controller feeds the switch centre tags and the outputs go to main track and prog track.

 

Edit to add my DPDT switch is centre OFF to provide a definite safe selection twixt main and programming selections.

Rob

Edited September 4, 2017 by RAFHAAA96

[smokebox]

Some DCC controllers, or command stations, don't have a current limited programming output. The Hornby Select being one of these. In this case the full track current is used for programming and if you use a switch to divert the power from the main track to the programming track the only real advantage is the convenience of not having to remove all the locos and stationary decoders (accessory decoders) from the main layout to prevent them being accidentally reprogrammed.

[Sunnysa]

If done properly, programing on the main is perfectly safe and will only program the designated loco.

 

Will not program any other loco on layout.

 

Have been doing it for many years without any problems.

 

Cheers

 

Ian

[Phil S]

Picking up on an earlier point with regard to Accessory Modules/Decoders wired into the layout - SOME would automatically re-pogram themselves at the same time as the Loco intentionally being programmed- using the same CV address and value: However, many, (and in my opinioon the better types) have  a ;Learn' button which needs to be pressed to put them in that receptive mode ... without doing that, they are unaffected.  Yet others have the equivalent in the form of a link between 2 contacts, and finally some, as with Loco decoders, use a 'Lock' CV to prevent changes being made.    HOWEVER - ALL THESE will be taking current from the controller during the priogramming sequence - as will any LIGHTING and other current consumers such as SOund decoers.

 

Especially with a new loco, the separate programming track has its advantages - it makes diagonosis of a problem easier - whether the controller offers 'Readback'/Feedback or not of existing values...    Note that PoM does not provide feedbacl/readback UNLESS Railcom(+) fitted decoders and controllers are used - its application is 'primarily' around 'teaking values' 'dynamically'.

 

I use a variety of controllers (Massoth, Roco/Fleischmann Multimaus, MultimausPro+ and CentralPro, and now Z21 with WLANmultimauses ....  The Massoth includes feeback/readback during programming [depending on programming option chosen], and, more importantly, confirms AFTER programming has beeb attempted, whether it has happened correctly. The 'Basic' Roco setup of Multimaus and Amplifier does not offer readback or a separate programing track -  BUT on our latest exhibition layout, whilst the MultiCentralPro porovides the main control ( and can provide reaback during programming), I have an electrically separate LOOP  which is controlled from the Basic Roco Multimaus:- This allows locos to be run in, or reporgrammed without stopping operation on the main layout, AND if the main layout stops for any reason - the LOOP is still running independantly, so keeping 'the layout' running. Programming WITHOUT feedback/readback is FASTER, and all that is needed to set loco addresses and most other values.  However:  I have also included a dcc-switched crossover which allows 'stock transfer' between the main and LOOP layouts .... It ALSO CONTROLS a Uhlenbrock RELAY which changes the LOOP power source over .... a loco, or more to the point, a UNIT train, such an HST can be driven on and/or off the layout - avoiding having to recouple all the coaches, especiall when multipin connectors are used.

[Nigelcliffe]

Hi All. I have seen a YouTube video ( or two) on wiring a programme track using a DPDT centre off toggle switch , and I followed this idea. And it has been claimed that testing a Decoder wired Loco on the programme track first

My question is "How is this track less likely to cause a Decoder to fry " as the same power is going to both sets of contacts.

Kevin

 

A more relevant question about the "programming track" with DPDT is the risk of damaging the DCC Command Station. 

 

If this track is just a length on a bench, not rail-connected to anything else, then the DPDT switch is fine (its how my workbench test track is setup).  You'll have no contact issue on the switch.  You can rapidly swap from "programming" to "run" on the length of test track.

Only during "programming" are you protecting the decoder, as soon as it is set to run you get the full command station potential current.   So, you should ensure everything is set to "programming" before putting a new loco onto the track, then attempt to read some CV values to confirm all is well.

 

If this track is a "siding" or similar, connected through to the main layout, then there is a serious risk that you need to be aware of.  If you leave a loco, or stock with metal conducting wheels, over the insulated joiners between programming track and rest of layout, and set the switch to "programming", you then connect your layout power to your DCC programming terminals.  That will probably destroy the programming side of your DCC system, requiring a trip back to the makers (I know several modellers who've done this).    So, I strongly recommend against such arrangements.    There is a slightly safer wiring arrangement with a four-pole switch, and an isolating section between the programming track and the rest of layout.  That is safer, but seems a lot of faff for the end result.  

[Ron Solly]

With NCE,once you select Programming on Programming track mode,layout power is removed leaving reduced power on the  programming track.

 

I use the programming track when I first install a decoder if I can't find my decoder tester  https://www.ncedcc.com/online-store/DTK-Decoder-test-kit-p38322156

 

I then use Programming on the Main to be able to set speeds especially if trying to have two different locos run at the same speed for double heading/consisting

[imt]

With NCE,once you select Programming on Programming track mode,layout power is removed leaving reduced power on the  programming track.

 

 

 

I am sorry, but I don't believe that the statement is correct: see http://www.rmweb.co.uk/community/index.php?/topic/126071-i-think-i-just-fried-a-dcc-loco-chip-diagnosis-assistance-needed/

 

I absolutely agree with your point in using a programming track and the case for POM.  I (and some others) use an entirely separate programming track - not connected to the layout in any way.  I have a PCP attached to a piece of track and physically move my PowerCab handset.

 

The NCE PowerCab does NOT reduce the voltage to the program track when  "set Program Mode" is selected - well not for me anyway.  I have 13.5v AC in both cases.  I believe that what happens is that the commands are issued at a lower amperage and for only short bursts - but nobody seems to know for sure.  The NMRA standards require that "service mode" (as they call it) operates at "limited energy".  They go on to say "For the purposes of this STANDARD, limited energy is defined as 250 mA, sustained for more than 100 ms.".  I do not believe that this or any other standard REQUIRES that track voltage be reduced.

 

What the NCE PowerCab does as well is to test for a short circuit on the program track before it changes mode - another protection for a mis-wired decoder. 

 

Sadly none of this helped me - but it will help others if they understand exactly what is going on.

Edited September 12, 2017 by imt