Programming track

[Ron Solly]

Now while the Powercab may not remove the power from the layout, the  NCE Power Pro 5A control system  does.

I use the Power Pro as I have 5 people operate  on my  layout so the Powercab would not be viable.

Using Power Pro and Programming on  Program track, layout voltage is removed and programming track voltage is around 10v

[Nigelcliffe]

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 gave a reference to extensive document by Mark Gurries with oscilloscope traces, but a number of people have an aversion to going to a long established Yahoo group to read it - it would answer the questions in this and the other thread.  The same Yahoo group is where definitive answers to many NCE issues are found.   

[imt]

Now while the Powercab may not remove the power from the layout, the  NCE Power Pro 5A control system  does.

I use the Power Pro as I have 5 people operate  on my  layout so the Powercab would not be viable.

Using Power Pro and Programming on  Program track, layout voltage is removed and programming track voltage is around 10v

 

The PowerCab and PowerPro are two very different beasts - and this probably shows where the base system (the PowerCab) is a "cheap" starter system.  The PowerCab has only ONE feed so it cannot of itself cut power to the main layout - an add-on (an auto switch) is provided should that be required. This is the problem with statements like NCE (or any other supplier) does X - I completely misunderstood and being fixated on my problem (which your system obviously doesn't have) I questioned your statement of fact.

[imt]

I gave a reference to extensive document by Mark Gurries with oscilloscope traces, but a number of people have an aversion to going to a long established Yahoo group to read it - it would answer the questions in this and the other thread.  The same Yahoo group is where definitive answers to many NCE issues are found.   

 

Thank you very much Mr. Cliffe, your assistance is as ever greatly appreciated.  In my area of expertise we are very cautious of using services which have less than clear bills of health on user security.  I and many others keep clear of Yahoo on that basis alone. 

Edited September 12, 2017 by imt

[shibushe]

This how I do it works fine. bearing in mind the fine detail of Locos nowadays you don't want to keep picking them up and replacing them.

My Prog track is incorporated in a running line insulated at both ends.

Once I have set a Cv say Cv5 Top Speed its a simple matter of running it out on the main.

If the setting is fine then that's it.

If its not then run in back to program and rest.

[imt]

This how I do it works fine. bearing in mind the fine detail of Locos nowadays you don't want to keep picking them up and replacing them.

My Prog track is incorporated in a running line insulated at both ends.

Once I have set a Cv say Cv5 Top Speed its a simple matter of running it out on the main.

If the setting is fine then that's it.

If its not then run in back to program and rest.

 

That sounds very sensible to me.  When you say "insulated at both ends" do you mean you have an isolating section at both ends?  I have heard it suggested that it is sensible to keep the main and the programming track isolated from each other, not just rail breaks. This is presumably to prevent accidental driving from one to the other when having program mode switched on. If you have a secure system of either one or the other the problem of course does not arise.

 

I particularly agree with your point about lifting locos about.  I have some sight problems so I always try to avoid using hands-on.  I have some PECO loco lifts which I use to store and move my locos about.  When fitting decoders though - needs must!

Edited September 12, 2017 by imt

[Ron Solly]

Ah yes, I should have said in my first post that NCE PowerPro removes layout power when using programming track mode. I hadn't even thought about the starter unit of Powercab.

 

Problems with Yahoo groups - I have been a  member a few and never had any problems.

[Sunnysa]

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.

If programing (service) mode is being set up properly in system and there is still full voltage on programing track then there is something wrong with system surely.

 

The only time there is voltage on programing track is when a command is sent to change or read a CV which is sent in a very short burst. Hence a loco will sometimes lurch or jump when command is received.

 

 I speak from 22 yrs experience of using DCC also a few yrs ( now retired) selling DCC in a large hobby shop.

 

A decoder tester is a must in any serious DCC modelers kit. It will save a lot of fiddling about and frustration.

 

 Cheers

 

Ian

 

.

[Torper]

In the NCE PowerCab system there is full voltage in the rails when set to Programming Track mode - I know because I and others have tested it with a multimeter.  I understand, however, that there is reduced current (amps) though I have received no definite confirmation of that.

 

DT

[imt]

Ah yes, I should have said in my first post that NCE PowerPro removes layout power when using programming track mode. I hadn't even thought about the starter unit of Powercab.

 

Problems with Yahoo groups - I have been a  member a few and never had any problems.

 

Please, it was my fault that I misunderstood you.  However such action is not necessary.

 

Please read Mr. Gurries at https://sites.google.com/site/markgurries/home/technical-discussions/program-track/nmra-programming-track

 

I am pleased that you have not had problems with Yahoo.  If you want to know what I am talking about try Googling "Yahoo security breach".

Edited September 13, 2017 by imt

[NIK]

In the NCE PowerCab system there is full voltage in the rails when set to Programming Track mode - I know because I and others have tested it with a multimeter.  I understand, however, that there is reduced current (amps) though I have received no definite confirmation of that.

 

DT

 

Hi,

 

Using my NCE Power Cab I put a 9 ohm power resistor across the track output and the Power Cab provided about one Amp in normal operating mode and in programming track mode. The output voltage was the same in both modes.

 

Regards

 

Nick

[Torper]

Fine...........except that Mark Gurries, who appears to be something of an NCE guru, takes the view that the PowerCab in Programming track mode meets the NMRA definition of a true Programming Track in that "its power (Current) is intentionally limited to only allow safe programming of the decoder and nothing else".  If it wasn't there would be no point in it having a "Programming Track" mode at all.

 

I have submitted an inquiry to NCE asking for clarification but am not holding my breath for an early answer.

 

DT

[imt]

Hi,

 

Using my NCE Power Cab I put a 9 ohm power resistor across the track output and the Power Cab provided about one Amp in normal operating mode and in programming track mode. The output voltage was the same in both modes.

 

Regards

 

Nick

 

Look I am way out of my league here, so this may be a very silly question BUT surely all you have proved is that a certain amperage can be drawn and NOT what the PowerCab actually uses to write to a DCC decoder when in program track mode.  I understand all would be revealed to me were I inclined to use Yahoo, but with respect I don't have a long enough spoon. 

[imt]

If programing (service) mode is being set up properly in system and there is still full voltage on programing track then there is something wrong with system surely.

 

The only time there is voltage on programing track is when a command is sent to change or read a CV which is sent in a very short burst. Hence a loco will sometimes lurch or jump when command is received.

 

 I speak from 22 yrs experience of using DCC also a few yrs ( now retired) selling DCC in a large hobby shop.

 

A decoder tester is a must in any serious DCC modelers kit. It will save a lot of fiddling about and frustration.

 

 Cheers

 

Ian

 

.

 

Thanks Ian.  Mr Gurries would disagree with you https://sites.google.com/site/markgurries/home/technical-discussions/program-track/nmra-programming-track

 

But I really do want to find the facts - since I don't want another damaged decoder.  It wasn't the decoder that didn't work - it did when first inserted - so a decoder tester wouldn't really help me.

[Crosland]

Using my NCE Power Cab I put a 9 ohm power resistor across the track output and the Power Cab provided about one Amp in normal operating mode and in programming track mode. The output voltage was the same in both modes.

 

"about 1 Amp" through 9 ohms is only 9 V, which is on the low side for DCC track voltage. How did you measure the voltage and current, given the well known problems of measuring the AC square wave at up to 10 kHz with hobbyist equipment.

[ianjeffery]

I have a powercab for my main layout, and for my programming track, i have a short strip of track, off the main layout connected to a sprog. I use JMRI to program locos.

 

i find it much easier, and there is no chance of programming the wrong train. i have to physically lift the train over to the track ( its slightly below on a shelf )

[shibushe]

That sounds very sensible to me.  When you say "insulated at both ends" do you mean you have an isolating section at both ends?  I have heard it suggested that it is sensible to keep the main and the programming track isolated from each other, not just rail breaks. This is presumably to prevent accidental driving from one to the other when having program mode switched on. If you have a secure system of either one or the other the problem of course does not arise.

 

I particularly agree with your point about lifting locos about.  I have some sight problems so I always try to avoid using hands-on.  I have some PECO loco lifts which I use to store and move my locos about.  When fitting decoders though - needs must!

Yes Insulated fish Plates both ends. Program output is fed to this piece of track. Once into Prog mode the voltage is reduced to protect the decoder from frying incase there is a fault within the loco or decoder.

[imt]

Yes Insulated fish Plates both ends. Program output is fed to this piece of track. Once into Prog mode the voltage is reduced to protect the decoder from frying incase there is a fault within the loco or decoder.

 

Are you SURE that the voltage is reduced or are you just repeating the commonly held view?  There is no NMRA requirement that the voltage be reduced.

 

I have a powercab for my main layout, and for my programming track, i have a short strip of track, off the main layout connected to a sprog. I use JMRI to program locos.

 

i find it much easier, and there is no chance of programming the wrong train. i have to physically lift the train over to the track ( its slightly below on a shelf )

 

Yes that's what I finally worked out too.  I use PECO loco-lifts to do the lifting about in, but a separate track does seem to be a good idea.  I am increasingly being drawn to the Sprog idea too (a better investment I am beginning to think than a decoder tester) and I have used JMRI in the past via an NCE USB adapter, its just freeing up a computer to dedicate to the job that is the pain.

Edited September 13, 2017 by imt

[Torper]

I think we've established that using the PowerCab in Programing Track mode the voltage is not reduced.  Several of us have tested it with multimeters and have come to this conclusion.  And as you say, NMRA does not require a reduction in voltage: "(The) programing track can have any voltage between 7V and 22V because you are not running a train.  You are only programming a decoder.  In practice the voltage is typically 12V anyway but there is not a requirement" (Mark Gurries).

 

Track current, ie amperage, must however be reduced to comply with the NMRA definition which is "The maximum programming current is 250mA which is the same as 0.25Amps under any and all conditions."

 

I cannot believe that the PowerCab in programming track mode does not comply with that.  If it does not, what is the point of it having such a mode?

 

DT

[NIK]

"about 1 Amp" through 9 ohms is only 9 V, which is on the low side for DCC track voltage. How did you measure the voltage and current, given the well known problems of measuring the AC square wave at up to 10 kHz with hobbyist equipment.

 

Hi,

 

I used a DMM that displayed 12.6V from the NCE Power Cab with 13.8V DC power supply when on 20V AC range.

I though that was reasonably accurate (not knowing the internal circuitry of the Power Cab).

I can't explain the voltage droop (the DC power supply voltage didn't fall when 1 amp was flowing) but it may be due to the cable I used between the Power Cab and the Power Cab Panel (its not the original cable) - so that could explain why any current limiter in the Power Cab didn't work when in programming track mode.

However my Power Cab did report a short circuit on its display - it just didn't seemed to do any thing about it.

 

Regards

 

Nick

[imt]

......

However my Power Cab did report a short circuit on its display - it just didn't seemed to do any thing about it.

 

Regards

 

Nick

 

I don't thing it can actually do anything about it of itself.  I think it relies on you to remove the loco or whatever.  The PowerCab when in normal mode simply cycles round resetting itself - and will presumably eventually fry.  Mine did get warm as I sought the short on one occasion.  In program track mode it is also up to you - but it does tell you and it doesn't get hot about it.

[ianjeffery]

 

........  I am increasingly being drawn to the Sprog idea too (a better investment I am beginning to think than a decoder tester) and I have used JMRI in the past via an NCE USB adapter, its just freeing up a computer to dedicate to the job that is the pain.

 

How about a raspberry pi and a sprog - you can even get a sprog shield ( http://www.sprog-dcc.co.uk/pisprog.shtml ) . find a cheap hdmi TV on ebay and your almost there. The Pi3 even has built in wifi.

 

Sprogs are great. its so easy to use and i can take it anywhere with me - so when i program my dcc interfaces ( www.dccinterface.com ) i can take a small strip of track and a sprog and my laptop and test them anywhere.

[imt]

How about a raspberry pi and a sprog - you can even get a sprog shield ( http://www.sprog-dcc.co.uk/pisprog.shtml ) . find a cheap hdmi TV on ebay and your almost there. The Pi3 even has built in wifi.

 

Sprogs are great. its so easy to use and i can take it anywhere with me - so when i program my dcc interfaces ( www.dccinterface.com ) i can take a small strip of track and a sprog and my laptop and test them anywhere.

 

Thanks for the link.  SPROGs seem to have moved on a lot since I last looked - the Pi-SPROG system seems to be a complete replacement for the PowerCab (if you are not frightened of Linux or computers) with the addition of JMRI if you are in to all that complication.

[Izzy]

Having used a sprog (II v 2.7) + JMRI/Decoder Pro for some years with a variety of computers, Win XP/7 and Mac I would say that it is I feel the best and safest route while also being very flexible and quite easy to use. Well worth the investment IMHO.

 

I remain skeptical of the NCE programming mode. The problem seems to be the different ways the NMRA recommendations are being interperated. Yes there is nothing wrong with have full voltage track power, the issue being to my mind that while this is delivered at a lower amperage it is not momentary as per the NMRA specs of 100ms, but continuous. 250ma at any continuous voltage between 7-22v is more than enough to run many motors at quite a speed, and to my mind capable of frying electronic circuits when flowing the wrong way due to a short etc.

 

Just my take on it, not being a NCE user.

 

Izzy

[imt]

Having used a sprog (II v 2.7) + JMRI/Decoder Pro for some years with a variety of computers, Win XP/7 and Mac I would say that it is I feel the best and safest route while also being very flexible and quite easy to use. Well worth the investment IMHO.

 

I remain skeptical of the NCE programming mode. The problem seems to be the different ways the NMRA recommendations are being interperated. Yes there is nothing wrong with have full voltage track power, the issue being to my mind that while this is delivered at a lower amperage it is not momentary as per the NMRA specs of 100ms, but continuous. 250ma at any continuous voltage between 7-22v is more than enough to run many motors at quite a speed, and to my mind capable of frying electronic circuits when flowing the wrong way due to a short etc.

 

Just my take on it, not being a NCE user.

 

Izzy

 

Thanks for the ideas.  I will I think put a Sprog in some form or other on my Christmas list.  I must think what I really need as opposed to the all singing all dancing possibilities!

 

Your views on The PowerCab are interesting.  I am about to try to refit a decoder into my Lima chassis and program it - I'll bear your views in mind.