PC Sd70ace Up, Banking Comm, Reversers Unsynchronized

Discussion in 'Technical Reports' started by shacheld, Nov 26, 2021.

  1. shacheld

    shacheld New Member

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    SD70Ace UP, Banking COMM, Reversers Unsynchronized

    Consists with Distributed Power.

    Banking COMM on in Lead Unit, off in Rear Unit.

    Reversers synchronize initially at startup.

    After the Throttle is moved in the Lead Unit, the Reverser in the Rear Unit is stuck in its last position.

    Can be fixed by turning Banking Comm off and back on in Front Lead Unit.

    This is unnoticeable initially because the Reversers are in the right position.

    It only becomes apparent when Rear Unit is stuck in neutral because the Throttle was moved before the Reverser. Or changing direction, Lead Unit in Reverse, Rear Unit stuck in Forward (Cabs facing same direction).

    Rear Lead Unit stuck in neutral, consist doesn’t have enough power, and no dynamic brake in Rear Lead Unit.

    Observable from the window of the Rear Unit.

    Repeated this with various SD70Ace UP consists with Rear Units (Banking COMM, Distributed Power), both on Sherman Hill and Sand Patch Grade.
     
    Last edited: Nov 30, 2021
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  2. shacheld

    shacheld New Member

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    Front Unit in Forward
    Lower Right HUD Shows Front Unit
    upload_2021-11-26_16-45-43.png


    Rear Unit in Neutral (Banking Comm, Distributed Power)
    From Window of CAB
    Lower Right HUD Shows Front Unit in Forward at same time
    upload_2021-11-26_16-49-1.png
     
    Last edited: Nov 27, 2021
  3. shacheld

    shacheld New Member

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    Front Unit in Reverse
    Lower Right HUD Shows Front Unit
    upload_2021-11-26_17-2-53.png


    Rear Unit in Forward (Banking Comm, Distributed Power)
    From Window of CAB, CABs facing same direction
    Lower Right HUD Shows Front Unit in Reverse at same time
    upload_2021-11-26_17-5-22.png
     
    Last edited: Nov 27, 2021
  4. shacheld

    shacheld New Member

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    On further testing, if the throttle is moved from the window on the rear unit, the reverser will work again.
    Also if the Banking Comm is turned off and on again in the Front Lead Unit.

    Although when the throttle is again moved in the front unit, problem persists.

    The throttle movement remotely seems to be sticking the reverser.

    I noticed the throttle sticking the interlock in the front unit as well, but you can jimmy it to get it to work.
     
    Last edited: Nov 30, 2021
  5. Andrew Beeman

    Andrew Beeman Member

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    In real life no trailing or DPU units should have the reverser inserted. Units will then only respond to the lead unit. In real life if you leave a reverser inserted on a trailing unit, it will not respond to any directional input from the lead loco
     
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  6. shacheld

    shacheld New Member

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    This may not be prototypical to real life, more of a problem in game that is causing power and braking issues.

    Thanks for your thoughts.
     
  7. Andrew Beeman

    Andrew Beeman Member

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    I dont seem to have any issues with the SD70Ace in game as long as the reverser is centered and removed in all trailing locos

    To remove the reverser, set it in neutral and click just above it on the control stand and it will remove it

    The game was not coded to handle the reverser being inserted when the unit is trailing, I have had the issues you speak of myself, but only if I leave the reverser in
     
  8. shacheld

    shacheld New Member

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    When using Banking Comm on Distributed Power Units (Engines at either end of the Consist), the Reverser automatically inserts and the Control Switches turn on in the Rear Lead Unit when you turn on the Banking Comm in the Front Lead Unit.

    Your thinking of Engines connected together without Banking Comm, connected by cable (Engines at the same end of the Consist). These are not Distributed Power Units. They are Multiple Units.

    In a Distributed Power Unit Consit you could have Four Front Engines and Two Rear Engines. The Front Lead Unit is connected by Banking Comm to the Rear Lead Unit. The Front Trailing Units are connected by cable to the Front Lead Unit and the Rear Trailing Unit is connected by cable to the Rear Lead Unit.
    Reversers in and Control Switches on in the Front Lead Unit and the Rear Lead Unit.
    Reversers out and Control Switches off in Front Trailing Units and Rear Trailing Unit.
    Banking Comm on in Front Lead Unit only.

    This is how Distributed Power Units are handled by TSW2 using Banking Comm.
    There are charts in the TSW2 Steam Guide section that lay this out in a more readable fashion if you prefer.
     
    Last edited: Nov 27, 2021
  9. TrainSim-Matt

    TrainSim-Matt Executive Producer Staff Member

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    Interesting discovery - i'll relay it to the team, thank you!
     
  10. shacheld

    shacheld New Member

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    Thank you Matt!
    Please let me know if I can help any further!
     
  11. shacheld

    shacheld New Member

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    Test Consist
    SHSD70AceDPU_02.JPG

    Rear Lead Unit Video
     
  12. shacheld

    shacheld New Member

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    I hope this was helpful.

    I noticed Matt sticking to this procedure in his streams on Sunday.

    I imagine that some people with US Train DPU starting experience will notice that this procedure is unlike previous Locomotives.
    Normally you would increase the throttle while in neutral to increase RPM and speed air increase.
    But you can't do this with the SD70Ace UP because the reverser gets stuck.
    Although you can put the reverser in forward on the SD70Ace UP and hear a slight increase in RPM.

    Again to unstick Rear Lead Unit Reverser turn the Banking Comm off and on again in the Front Lead Unit.
    You'll see Matt doing it in the streams.


    For Individuals with Experience. (These are only the steps needed for air! Other steps not included.)

    Front Lead Unit.
    1. Reverser in Neutral
    2. Throttle to 3 or 4
    3. Audible Increase in RPM causes Air Pressure to Increase Faster
    4. Air Pressure at Desired Level
    5. Throttle to idle
    6. Banking Comm Turn OFF and ON again (reset)
    7. Move Reverser Back and Forth (reset)
    8. Move Reverser to Forward
    9. Continue

    Thanks
     
    Last edited: Nov 30, 2021
  13. solicitr

    solicitr Well-Known Member

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    There is alternative approach, if you want to speed brake charging by running higher engine RPM (although I'm not sure if the game actually models this): Front cab reverser forward, switch off generator field, rev engine, after brakes are charged return to idle and turn gen field back on. This keeps the air compressor running without sending current to the traction motors; for our purposes here, it avoids the trail-unit reverser glitch because you never move the reverser.
     
  14. shacheld

    shacheld New Member

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    Great Idea! I'll do that.
    I was noticing something similar to this procedure when I watched some great sounding startup videos of the SD70Ace.
    They left the Gen Control Switch off in startup.

    There are TWS2 intro scenarios that describe this procedure with other US Locomotives.
    I seem to be getting faster buildup times?
    Sounds like RPMs increase and it makes me feel better about the wait.
     
  15. shacheld

    shacheld New Member

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    Another circumstance which I have run across while creating the test Consist, is having to use the below procedure to move the Consist around. Every time I use the throttle I have to reset the reverser.
    I also have this problem when restarting my saved game of the test Consist. I have to reset the reverser.

    Front Lead Unit.
    1. Reverser in Neutral
    2. Throttle to 3 or 4
    3. Audible Increase in RPM causes Air Pressure to Increase Faster
    4. Air Pressure at Desired Level
    5. Throttle to idle
    6. Banking Comm Turn OFF and ON again (reset)
    7. Move Reverser Back and Forth (reset)
    8. Move Reverser to Forward
    9. Continue

    I am sure this is affecting anyone trying to save game.

    The reverser needs to be cleared constantly.
    I even had it stick so bad it wouldn't clear at all for about 4 tries. I had to turn the banking comm off in the front lead unit then move the throttle and reverser in the rear lead unit to get it to work again. In the process the front lead unit stuck also and had to be cleared.
     
    Last edited: Dec 2, 2021
  16. shacheld

    shacheld New Member

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    I think somehow in the programing of the Locomotive the Throttle and Reverser Interlock aren't working correctly.
     
  17. Wesley Alves

    Wesley Alves New Member

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    I think the dynamic brake is broken on this loco aswell.... On the downhill parts in Sherman Hill and Sand Patch, I can't hold the train to the speed limit. It basically gets runaway everytime. I don't know If It has anything to do with the issue that you're talking about but there's definetely something funny with the dynamic brake.
     
  18. solicitr

    solicitr Well-Known Member

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    A hundred-car train isn't going to be held by dynamics alone on a steep downhill.
     
  19. shacheld

    shacheld New Member

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    If the Rear Lead Unit Reverse is stuck in Neutral the Dynamic Brake doesn't work.
     
    Last edited: Dec 2, 2021
  20. solicitr

    solicitr Well-Known Member

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    It shouldn't have the reverser handle inserted at all. The rear MU cabs should all be in shutdown state.
     
  21. shacheld

    shacheld New Member

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    Sorry typed that wrong, got it fixed. I meant DPU Units.
     
  22. Wesley Alves

    Wesley Alves New Member

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    I've never had any issues with that on Sand Patch...And when I do a timetable run there with a 40/50-car train (SD70) that's where this happens. It's either a bug , or I can't conduct the SD70 properly. lol
     
  23. shacheld

    shacheld New Member

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    Its not your Conducting! I've Tested this a lot. Its definitely a glitch.
     
  24. Nick Y

    Nick Y Well-Known Member

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    See my reply in another post about the dynamic brakes.
    https://forums.dovetailgames.com/th...s.49440/#:~:text=Just a point,a runaway train.
     
  25. Wesley Alves

    Wesley Alves New Member

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    Ok, thanks
     

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