DCC Loco Conversions - 15 - Testing and Programming Tools

Discussion in 'DCC Control' started by Jim Freight, May 1, 2022.

  1. Jim Freight

    Jim Freight Full Member

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    Before I commence on the actual conversions and the fun I have had with some of them I thought it would be useful to give an overview of the tools I use at this stage so I can just refer to them in the conversions.

    All DC current measurements are made whilst powering the locos with a Hammant & Morgan variable transformer unit on full wave rectification using a meter unit I assembled decades ago. This was calibrated against an in house calibrated AVO multi-meter from my workplace.

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    My indoor test track as opposed to the layout consists of a 4ft length of code 100 on a strip of wood which is long enough to check for smooth running and initial acceleration, deceleration and speed settings. This is connected to the Lenz LZV100 command station as the 'Main'.

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    A Hornby rolling road which is connected to the LZV100 as the programming track.

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    The LZV100 is connected to the laptop via the Lenz USB/LAN interface 23151 by Ethernet cable.

    Using the LAN connection is much more reliable than the USB port, especially as the USB interface protocol appears to be a very different version compared to the same unit used in the shed for the layout. The two USB drivers for each are totally incompatible with each other and terminally corrupt each other if mixed. So here and in the shed I use the LAN interface which means the laptop can be easily moved between the two without issues.

    The LAN interface also allows the Lenz CV editor and the JMRI Decoder Pro (Ref 15.1) to be connected at the same time.

    I run my DCC at 13V and not the default of 16V to reduce heat dissipation at the decoders, the efficiency of the power distribution on the layout has meant that there is very little voltage drop across the layout so 13V is fine.

    Most locos when run at 12V on DC run like F1 cars, that is not for me. When you adjust the DCC track voltage it means it will also vary the top speed of your locos, so it is best to set it early such that you do not need to re-set all the speed setting CVs of each loco decoder to suit. In reality if my locos were running on DC even the express locos would only be provided with a nominal 8V, so a lower DCC track voltage is fine.

    I universally keep to 28 step mode with the automatic analogue option turned off.

    Initially a Bachrus rolling road with speed sensing add-on was used to set up loco speed CVs, however, IMO this was very expensive and weakly made, the speed sensor mechanism too fragile, it replaced one side of one set of rollers, wore out after about 50 locos!

    Before fitting a decoder I test it via the ESU Decoder Tester (Ref 15.2) using the Lenz CV editor and then set up the decoder using the JMRI Decoder Pro tool which allows me to save the CV data. Decoder Pro also allows an entry to be duplicated and renamed, handy for programming multiple similar locos using the same decoder.

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    The setup with a laptop, this was bought as a refurbished machine, low on processing power, disc and memory, but runs Windows 7 well enough for this job, and running my Traffic Generator and MPD software. It is also of rugged design, probably used by travelling salesmen in its first life, so is well up to workshop and railway use.

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    Work on locos, decoders and basic CV settings for start voltage, mid, max and normal/reverse operation are also logged in an Excel spreadsheet.

    As stated in an earlier article I do not use the stall current to determine the required rating of decoder, instead I use the onset of wheelslip of the loco against a buffer or finger, most of my Dublo/Wrenn locos running light on the rolling road take 0.25A and slip at about 0.5A on the test track.

    The main running track length is known and a printed table of lap times and the equivalent train speeds can confirm they are realistic, lap times are measured with an iPod Touch in stopwatch mode.

    Power consumption can also be checked on DCC with the RRamp meter (Ref 15.3) shown to the left of the laptop, a bit pricey IMO but is rather specialised, I generally use it on the layout. Mine appears to read 0.5V high but there are no user accessible adjustments. The reason I think it reads high is that it is not only high according to the set voltage on the LZV100 but also according to an independent digital oscilloscope. Power input to the meter for current readings must be from the left hand side to eliminate the current used by the meter. Overall a very useful tool for both loco and track testing.

    Final testing is performed on the layout with mid and max speed CVs adjusted for realistic top speeds, after a while these settings can be easily estimated and just tweaked on the layout.

    Next the locos ...

    Discussion always :welcome:

    Jim

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    References


    15.1 JMRI Decoder-Pro

    https://www.jmri.org/

    15.2 ESU Decoder Tester

    https://www.esu.eu/en/products/decoder-tester/

    15.3 RRamp Meter

    https://www.digitrains.co.uk/rrampmeter-v2.html
     
    Last edited: Feb 24, 2024
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  2. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    I’ve been using a USB interface with decoder pro for nearly 20 years - Sprog DCC https://www.sprog-dcc.co.uk/ as an alternative. It allows programming the same as ever with decoder pro but can also run a layout from either a laptop or you phone/tablet as a throttle. I understand it can also cover points etc, but I’ve never tried this.
     
  3. Jim Freight

    Jim Freight Full Member

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    Hi Andy, I use some old iPod Touch (2nd Gen) as wifi based throttles using an old version of TouchCab (latest does not run on their OS) they're very useful when I want to walk with the trains, that feature was the only missing feature of the Lenz system when I committed to it in 2013.

    Most of my points are Mercontrol wire in tube based, they are only electric in places that access for Merc would be very difficult, in some places it is still hand from the sky, so I shan't be using DCC for anything but driving in the (ever shortening) foreseeable future :avatar:

    Jim :)
     
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  4. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    We have it set up via Wi-Fi on my dads outdoor layout. Providing no track issues (as sometimes happens in sunlight with wood and metal etc expanding) we can sit at the table with a cuppa and drive from there whilst pressing the functions.

    for the £55 that a Sprog is, it may be worth the swap for modern locos. I don’t honestly know if they have the ampage for dublo locos in fairness.
    But for anyone starting DCC, it could well be a budget price controller and programmer in one that covers all systems.

    I use Wi-Throttle as my app on my iphone, but my dad has an Android tablet, and we can run both at the same time on the same system for anyone who is interested?

    here are some screen shots.
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    a loco roster of pre selected (And named/numbered locos) it shows the name and their 2 or 4 digit address depending on what we have selected.

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    Or you can do it by a number pad

    CC275910-3958-4455-9B19-5AD64FF2DECE.png and of course the throttle. I have mine on two at this time but in some devices you can have 3 (I think the max is 4?)

    with any pre filled in locos you can change the labelling for the F numbers to text to say what the function is, so F1 would become sound on/off, f2 would become long whistle, f7 say becomes fireman’s breakfast. (As I’m not near my layout I can’t select a loco to demonstrate)

    hope this is helpful for anyone considering a different type of controller rather than going the £2-300 route straight off..

    Andy
     
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  5. Jim Freight

    Jim Freight Full Member

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    Hi Andy.

    Well the amperage for a Dublo loco really depends on whether the loco has a healthy Alnico or a NEO magnet fitted and is well serviced.

    Also whether you rate them on wheel slip or stall currents, it's a matter of probability, I consider the risk of stall as minimal, and if a Dublo loco takes 0.75A on DC that is often due to lack of magnetic field strength and then you are more likely to incinerate the armature than the decoder, IMO £20 decoders can be easier and cheaper to replace than some armatures. :scratchchin:

    Jim
     
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  6. Andy_Sollis

    Andy_Sollis Staff Member Moderator

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    Very true Jim. Very true.
    I remember years ago Dad having his Dublo Duchess converted to zero 1. Wasn’t a great success, but then neither was zero 1!
     
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