Speed adjusting For Tandem units with DCC

Discussion in 'DCC & Electronics' started by stashu45, Oct 2, 2005.

  1. stashu45

    stashu45 New Member

    I just bought my first and I hope only Digitrax DCC Unit, The Super
    Chief 8amps with radio. I need help with programming, I've tried
    reading the manuals and am getting no where. My problem is this I
    a Broadway Limited set of E7A and E7B and right now I am using the
    default address of 03 on both units. The problem is that the 7B runs
    faster then the 7A. The B starts moving at about a speed of 7-8 on
    throttle while the A unit starts at about 13. How can I adjust these
    units so I can run them in tandem where they will aid one another not
    have the A unit hinder the B unit. Also where this information is
    available in either the manuals or other books in simple english.
    you for your time
  2. Union Pacific

    Union Pacific Member

    this may not be corect

    I am not the smartest DCC guy I do not have a set either (christmas:D )
    I think you could get unit A at a good speed on the right throtle then B at a good speed on the left throtle and drive them that way. another thing but Iam not shure would it be possible to hook up some resistors from the track power to the motor :confused: thats just my 2 cents don't qoute me on any of this I am just giving an EDUCATED GUESS.

    thanx, Ben
  3. stashu45

    stashu45 New Member

    For Tandem Units Reply

    Thanks Ben for your response. But I have the problem solved. I had to go to BLI's web site and download their manual because the Eunits are BLI and they use QSI decoders. I had to change CV#2 from the default of 32 to the following: On the "A" unit I set it to 50 and on the "B" unit I had to change it to 35. I also had to change CV#3 on the "A" unit to 1 from 0. Now they run just great.Those were the only changes that I made. I"ll run like this for awhile and see what happens. Once again Thanks.

  4. tillsbury

    tillsbury Member

    Errrm, you've bought the best DCC system, so why not spend a short while reading up on the manuals? First off, change the addresses -- they're only set on 3 so you can set them to what you want. One good way is to set the address of each loco to the last two digits of its numberboard (then you can remember).

    So for example, if your loco is number 710, to set the address to 10, just put it on the programming track, press "PROG" until the display says "Pg", and the top left of the display will say "AD2?" (asking what the 2-digit address should be). Press the DISP button and it'll ask the loco -- the answer 3 should come up (this shows you everything's working). Select 10 with the right-hand knob, and press Enter. The display should come up "Good". If you're paranoid, press DISP again and it'll confirm the change.

    The easiest ones to change are 2, 5, and 6. 2 is start voltage, 5 is maximum (i.e. top speed) and 6 is mid voltage (i.e. speed at 50%). Twiddle these until the locos run the same -- i.e. they *just* start at speed 1, and they are going the same speeds at 50% and 100% throttle. You'll probably also want to set CV's 3 and 4 to a value of 1 so you get some but not too much acceleration and deceleration. I normally set CV54 to 1 too, which allows you to use the F6 button to select "switching speed" (this drops the top speed and partially negates acceleration for switching work). That will mostly do it. Remember to Exit from programming mode by pressing the EXIT button.

    Now, you can select loco 10 on the right-hand knob and the other loco (let's say 11) on the left-hand knob, and run them independently.

    Once you've done this, you can just press the "MU" button, and it'll ask whether you want to add or remove a loco (+ or -). Press + to add loco 11 (the one on the left) to loco 10 (the one on the right). Now loco 11 doesn't exist any more (if you try to select it the display will show "cn" for consist). But loco 10 controls both locos at the same time, on the right-hand knob. Now you can select another loco on the left-hand knob and control it separately. To remove loco 11, select it on the left-hand knob (it'll come up with "cn"), press MU again and press - to remove it. Loco 11 will carry on running but be under the control of the left-hand knob.

    All you have to remember is that the master loco is on the right, and the one you're adding or removing is on the left. Kind of the wrong way around, but that's the way it is.

    If you prefer, you can create a 'virtual' loco. For example, select loco 20 on the right-hand knob. It'll work fine, except you have no loco number 20. Now select 10 on the left, MU and + to 'add' it to loco 20. Now loco 20 controls loco 10, as it's part of the consist. Then select loco 11 on the left and MU and +. Now loco 20 is both 10 and 11 consisted together.

    This way you can consist any combinations of locos together as and when you want, and control each set of them on one of the knobs.

    Then later you can look at the more trick parts of the manual, where it describes how the lights should respond when the loco is part of a consist -- that can get fun...

    Try it all and see... you can't go too far wrong because there's a "reset to factory defaults" -- if you really muck up a loco just put it on the programming track in Pg mode and reset all the CV's (I can't remember which CV you set, is it 7?), it's in the book...

    On the Super Chief, you can program most things in ops mode (press PROG until it says "Po"), and you can program CV's on any loco while it's on the mainline.

  5. stashu45

    stashu45 New Member

    Thank you for the advice Charles. I read the manuals, but some times that isn't enough. You need some one to say it again in their own words before it to make any sense, like you did. Also if you had looked at reply #3, you would have seen that I now have them working and I did change the address to 633 (number on side of engine).

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