DCC loco direction change

[Dave Lane]

Hi there. Started using a Digitrax Express Advance to control my layout. What's the best way to change a loco's direction to match another loco which is pointing the other way for double heading, eg a pair of class 20s? The instructions seem to suggest all locos have to physically be pointing in the same direction to work in multiple. Seems daft that a system from America, know for multiple loco trains doesn't have a simple way of doing this.  

[RFS]

You can do this by setting up a DCC consist which should be explained in your Digitrax manual. Basically you assign each loco to the consist and also which direction it is to travel in. The consist is assigned a unique number and you drive it via this number. 

[Nigelcliffe]

Depends what you're trying to do: 

 

• Permanently changing a loco - alter CV29 to change the normal direction of travel. 
• Manually setting Advanced Consists,  add 128 to the consist address you set in CV19 for that loco. 
• System aided Consists  -  there is usually something in setting up a consist , as RFS outlines above.  

[geoff]

Dave, if you mean two class 20s coupled nose to nose just set one to run forwards and the other to run in reverse and , on my DT 402, press "MU" and + and the two locos will run together in which ever direction you choose. I believe Digitrax calls that basic consisting. 

 

Geoff

[CFL]

I don't think it is that simple. I was led to believe that just putting two or more locos (double or triple headed for the UK, a lash up for the US) requires careful matching of the locos, especially regarding their speeds. Basically if one loco is slower than the other then then the quicker loco will drag the slow one putting mechanical strain on it. I think that the locos had to be timed over a set distance to find their speeds and adjust to compensate but I may be wrong as usual.

[jpendle]

1 hour ago, CFL said:

I don't think it is that simple. I was led to believe that just putting two or more locos (double or triple headed for the UK, a lash up for the US) requires careful matching of the locos, especially regarding their speeds. Basically if one loco is slower than the other then then the quicker loco will drag the slow one putting mechanical strain on it. I think that the locos had to be timed over a set distance to find their speeds and adjust to compensate but I may be wrong as usual.

That's what I've done with my double headers and top and tail consists.

 

I either measure the speed using iTrain, iTrain then controls both locos and compensates for differences, or I do the same in the Z21 app and the Z21 app then does the compensation.

It especially important if you want to run two different locos in the consist, say a CL37 and a 47 or a Pacer and a CL150.

 

Regards,

 

John P