# Consisting



## Greg Elmassian (Jan 3, 2008)

One of the great features (in my opinion) in DCC is consisting.

Basically you want a way to control all the locos in a train with the same throttle.

There are 3 ways to do this, and each has advantages and disadvantages.

I'll describe them starting with the best way:

*Advanced consisting:*

The most advanced method in DCC (and others) is "advanced consisting", this is where the consist information is stored in the receiver/decoders themselves. 



The same "consist" address is put in each decoder, then they will all respond to this address.


This allows very flexible operation and customizing which features apply to which locos in the consist, such as lighting, sound, etc.


Also this allows the "normal" direction of a loco to be different when in a consist, so you can have forward and reverse make sense both in the consist, (where a loco micht be "backwards" and when a loco is cut from the consist (like cutting off helpers)


A big advantage is that only one command for speed and direction changes needs to be sent, rather than the same command sent each time for every locomotive.


In a large consist, or when running many locomotives, advanced consisting is the method to keep response to commands fast. 

*Universal consisting: *

Sometimes referred to as basic consisting or old style. This is where you tell the "system" what locos are in the consist, and then when you change speed or direction, separate commands for EACH locomotive are sent.


The problem here is that you will degrade throttle and system response since you have to send 4 times as many commands for a 4 loco consist for example.


Since the consist is only "known" to the controller, most systems don't have the feature control to light the headlight only on the lead engine, only honk the horn there, etc.


Also in most systems, if you have a locomotive "backwards" in a consist, then removing it from the consist usually leaves it backwards. 

*Address consisting:*

This is not really consisting, but "cloning" the address of locos, basically making them all the same address. This is really a poor way to solve the problem.


In real consisting, you can drive a loco up to an existing train and then join the consist. In "address consisting" all locos have the same address, so there is NO INDEPENDENT control of your locos. 



This is just like jumpering them all together. Why run DCC if you operate it like the 1950's?


This is only used when people just don't understand, or have some really old system that cannot consist, or limited addresses.


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## Greg Elmassian (Jan 3, 2008)

Bottom line, consisting is a great thing, and the better "mode" your system supports, the more fun running you can have.

It's very cool to cut a helper on or off a train without touching it, whether a steamer or rear end motive diesel power.

Also, this works for locos in the middle of the train.


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## Ted Doskaris (Oct 7, 2008)

Hi Greg,

One thought that comes to mind for all the consisting systems is what will happen to a long train on a layout that varies in grade and/or curves with locos on the front and middle or maybe pushers on the rear. The speed characteristics of all locos would have to be maintained to be the same or else the train could suffer. Can any of the 3 consisting systems you describe deal with that?

-Ted


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## Treeman (Jan 6, 2008)

They all should be speed matched.


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## Greg Elmassian (Jan 3, 2008)

Yes, step one is speed match the locos.

Step 2 is that when connected they will all share the load pretty well, and I think you would have no problem even on your layout.

It's also possible to program most sophisticated decoders to pretty much maintain speed irrespective of load. That would be going pretty far, but could be done by setting BEMF parameters.

When people want to consist, usually the first thing they do is run 2 locos "light" with a few feet separating them... if they don't match pretty well, then they guess it won't work.

In reality, when you add a significant load, the locos involved will slow down (which they do not in the running light example)... and they will share the load very well.

In your case Ted, I know you have pretty darn high loads getting up the helix, so it should work pretty well, although pushers will make it harder. I'd try locos at the head end and halfway through the train.

Greg


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