PC Tvm-430 Not Working As Intended

Discussion in 'Troubleshooting' started by Splynn, Dec 21, 2020.

  1. Splynn

    Splynn New Member

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    At the speed reduction from 320kph to 300kph approaching Aix-en-Provence, I get a flashing 320 display followed by a solid 300 after passing the TVM marker board. The emergency brakes get applied immediately after passing the TVM marker as long as I am above 300kph.

    If I'm understanding the TVM cab signals correctly, it means that the cab display is showing the enforced speed at the upcoming TVM marker, and not the current enforced speed. A solid number means the next displayed number will be either the same or higher, and a flashing display means the next number is lower.

    The way it works now seems like the TVM safety system is enforcing the speed limits 1 block too early. If the implementation of TVM is accurate as of now, a 000 display would automatically trigger the emergency brake no matter what speed I am traveling the moment I crossed the TVM marker, which is not the case in reality.

    I encountered a similar problem during the bad things scenario. My TVM display is showing a flashing 230 display, but the emergency brake was triggered while going only 176kph past a TVM marker board just because the next enforced speed is 170kph.

    As of now, I'm running the scenarios without arming the TVM safety system. There is no functional difference since the cab displays work regardless.
     
    Last edited: Dec 21, 2020
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  2. Sintbert

    Sintbert Well-Known Member

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    As far as i understand it, it should be very simple.
    A flashing speed means you should brake down to that speed bevor the next signal-board.
    A solid speed means that it is your current speed limit.

    Going from that there should be no possibility of a flashing 320.
    If i am in a 320 block and the next block is 300, then i should get a 300 blinking and not a 320 blinking.

    It should always display the combination of the current and next block speed limit.
    Current > Next -> Next blinking
    Current = Next -> Current solid
    Current < Next -> Current solid

    From Wikipedia on TVM-430:
    A digital display on the train driver's dashboard shows the maximum permitted speed for a train's current block, as well as a target speed based on the status of the line ahead.

    So on a line with max speed 320 it is impossible to become a 320 blinking cab-signal. This is a bug or implemented wrong.
     
  3. Splynn

    Splynn New Member

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    A flashing 320 is absolutely a valid cab signal for TVM as seen in this video of a TGV 2N2 en route to Marseille (320 to 300kph sequence at 12:25):
    .
    In the video, the train passes the flashing 320 at 308kph with no consequences.

    As you have correctly stated, a flashing TVM display means that the following signal board enforces a lower speed than the next board. If the line speed limit goes from 320 to 300, it should display: Solid green 320 > Flashing green 320 (telling me to prepare to slow down) > Solid diamond 300 (telling me to slow to 300 or less) > Solid green 300 (at the start of the 300kph line speed limit).

    What should happen is that I pass the signal board at 300-320, the display switches to solid 300, and TVM enforces 300kph at the following signal board.
    What does happen is that I pass the signal board at 300-320, the display switches to a solid 300, and TVM enforces 300kph immediately.

    What's happening in TSW is that TVM is effectively penalizing drivers when the train is not speeding.
     
    Last edited: Dec 23, 2020
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  4. Sintbert

    Sintbert Well-Known Member

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    So what should happen at that speed change would be:
    1. 320 solid and enforced
    2. 320 blinking and enforced
    3. 300 in black diamonds and 320 enforced
    4. 300 solid green enforced
    So that speed change would go over two blocks.
    Higher speed |> warning of a reduction |> signaled reduction |> enforced lower speed.
    But what TSW does is enforce the lower speed already on the signaled reduction.
     
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  5. Splynn

    Splynn New Member

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    That's right. TSW skips a step and enforces the lower speed without giving any time to slow down. A similar thing happens on the bad things scenario as well. I pass a flashing 230 at 190 > signal changes to a flashing 170 > emergency brake applied.
     
    Last edited: Dec 23, 2020
  6. joulz75

    joulz75 Active Member

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    From what I saw in a cabride on the LGV med between Avignon and Marseilles, and commentated by the driver himself, he said that he always keeps a safety margin (with a step forward), so for a flashing 270 he would reduce speed up to 230. Actually the behaviour in the game is like irl :)

    This is a paying video and it's in french haha, but if you're interested, you can find it here : https://www.railpassion.fr/videos/rp143-cabine-dun-tgv-duplex-de-lyon-part-dieu-a-marseille-saint-charles-2e-partie/ (around 11:00 for the explanation)
     
    Last edited: Jan 2, 2021
  7. prg350

    prg350 New Member

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    Im pleased I found this post as the TVM in this game is driving me nuts and not working as I expect. One of my favourite routes on Train Sim (old one) is London faversham and I have no issues with the TVM on the 395's, however following the same logic of solid number = current max speed in block, flashing number = the speed you need to be at by the beginning of next block, it continually penalises me for speeding when I don't believe I am. I want to turn the safety systems on for realism but can't because of continual emergency breaking due to this bug. Hopefully it will be fixed soon and the new London Faversham in TSW 2 will be correct.

    From my understanding at line speed it should go something like

    solid 300 - speed up to 300kph
    flashing 300 - no immediate action but the next block will have a different limit (could be 320 or 270 you don't know at this point)
    flashing 270 - start to decel so speed is at 270 by next block ( TSW is currently incorrectly saying I'm speeding as I'm over 270!!!)
    solid 270 - speed up to 270kph
     

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