3 GP lashup and TIU

It shouldn't matter. There must be something else happening like a chassis ground problem? I really don't know.

What Joe said.   can you address each engine separately and will each move?

Gregg posted:

What Joe said.   can you address each engine separately and will each move?

yes

Maybe I'm not posing the question right. How does the TIU or the software know whether or not the 3 are physically connected ? Apparently a physical connection is necessary for the lash-up to function as 1.

I'm not concerned about the fact that it doesn't move as I am curious to know the connection to the TIU and how it knows the 3 aren't physically connected

Am I wrong to think that if they're separated by a hair they should still run as if they were connected ? What tells what that they aren't connected anymore and how does it know that ?

There seems to me to be something special that happens when MTH engines are MU'ed together. It doesn't matter where they are in the train. If one runs slightly faster or slower, they will still get along and do their job of moving the train.

 I run 2 rail. There are smaller flanges on the wheels. Yet the train won't shove anything off the rails even when there's a pusher shoving.

Now this was with a much older version of DCS. I think these were simpler times. As bugs crept into the software, and patches and changes were made, the system seems to have gotten more complex.

 ( a bug to note was one that required multiple presses of the direction button to get PS2 and PS3 engines in the same running direction.)

dobermann posted:

Maybe I'm not posing the question right. How does the TIU or the software know whether or not the 3 are physically connected ? Apparently a physical connection is necessary for the lash-up to function as 1.

I'm not concerned about the fact that it doesn't move as I am curious to know the connection to the TIU and how it knows the 3 aren't physically connected

It doesn't care,

No, it's not.

The system doesn't care if they are touching or far apart. It still handles them the same way.

The TIU does not care if the units are connected together or not. What matters is that each engine be is the designated position relative to the others and in the the designated orientation i.e. facing forward or backward. That's how you build a consist with a mid-train and or end-train helper.

Chris

LVHR

How does the TIU or the software know whether or not the 3 are physically connected

The TIU has no idea if the lashup members are connected, or not.

Apparently a physical connection is necessary for the lash-up to function

No, a physical connection is absolutely not required.

Am I wrong to think that if they're separated by a hair they should still run as if they were connected ?

No, you're wrong to think that they have to be connected,at all.

What tells what that they aren't connected anymore and how does it know that ?

There's nothing to tell the TIU that the members are not connected, and the TIU doesn't care if they are or are not connected.

However, all members must be powered up and must get a watchdog signal at the same time. Alternatively, there;s one other way to start up a lashup after the DCS watchdog signal has come and gone. From page 105 of The DCS Companion 3rd Edition:

Missing the Watchdog Signal

If individual DCS engines miss seeing the watchdog signal, they can be either brought directly into DCS active mode by pressing the Start Up key or put into DCS stealth mode by pressing the Shut Down key. However, this is not the same for lashups.

If a lashup is powered on after the watchdog signal has come and gone, perhaps if its siding was toggled on after voltage appeared at the TIU channel outputs connected to its siding, there are two ways to put the lashup into DCS mode. One way to put the lashup into DCS mode is to turn off power to the inputs for the TIU channel that is connected to the track upon which the lashup resides, toggle on the siding and then re-apply power. The other way is to first highlight the lashup in the remote's Active or Inactive Engine list. Then, flip the toggle switch and immediately press the thumbwheel to select the lashup. It will come up in DCS stealth mode, dark and silent. This also works with individual DCS engines.

This and a whole lot more about DCS is all in MTH’s “The DCS Companion 3rd Edition!" This book is available from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at MTH's web store!

Engineer-Joe posted:

There seems to me to be something special that happens when MTH engines are MU'ed together. It doesn't matter where they are in the train. If one runs slightly faster or slower, they will still get along and do their job of moving the train.

 I run 2 rail. There are smaller flanges on the wheels. Yet the train won't shove anything off the rails even when there's a pusher shoving.

Now this was with a much older version of DCS. I think these were simpler times. As bugs crept into the software, and patches and changes were made, the system seems to have gotten more complex.

 ( a bug to note was one that required multiple presses of the direction button to get PS2 and PS3 engines in the same running direction.)

Now thats what I call a mixed freight train.

I have even created an MU or Double/triple header by placing an engine in the middle or the end of the consist.  When I am thinking about one, I will not have them coupled to see which engine is faster to place them in order fastest to slowest (front to back).  I do this each time I create an MU.  You can also create an MU of three engines associated with three separate trains to start all three at once and then use the address of the individual engines to adjust the slack as a faster train catches up with a slower one.  In my earlier layout I used the DCS "ALL" command for a specific TIU channel; however, because my TIUs are now in "super" mode the "ALL" command does not work unless all the other engines are not on a powered track.