E-Z Command address v the "Rest of the World"

[boomertom]

If you are familiar with the E-Z Command system you are aware that we are limited to addresses from 1 -9 (10 if you have an appropriate dc power pack). Or do we ?

The rest of the DCC world commonly uses a four digit address scheme.

My question is this - is an address set on a Bachmann system to let us say 4 equivalent to an address of 0004 set on a Digitrax or other similar system?

Tom

[Yampa Bob]

I once asked the question; "Is a two digit address of 03 the same as the single digit 3 on my EZ Command, the answer was "Yes".

Mathematically speaking, 0004 is the same as 4. Of course I have been wrong a few times in my life. 

[Jim Banner]

When is 4 not equal to 4?  When you compare DCC addresses 04 and 0004.  Address 04, by convention, is a short address.  Address 0004 by the same convention is a long address.  Short addresses can range as high as 127 and are stored as a single byte in CV1 of decoders.  Long addresses (also called extended addresses) require 2 bytes, which are stored in CV 17 and CV18.  Many decoders also allow a third address used for advanced consisting.  It is a single byte stored in CV19.

Some DCC systems allow you to use both short and long addresses in the range 0 to 127.  With these systems,  you can have one locomotive with address 04 and another with address 0004.  They will respond only to their own commands.  Other DCC systems, including Digitrax, disallow long addresses less than 127 to avoid confusion.  E-Z Command uses short addresses only and stores them in CV1.  Yes, E-Z Command button 4 selects address 04, etc.  And no, it is not equivalent to address 0004 (set by a system that can do so) because that is a long address.

If that has not confused you enough, maybe this will.  If you are using a locomotive with a decoder that supports advanced consisting, and the advanced consisting address has been programmed to an address in the range of 1 to 9 (or 1 to 10) then you can run that locomotive with E-Z Command using the advanced consisting address.  But you will not be able to change the address of the locomotive with the E-Z Command.  That is because E-Z Command can only program short addresses in CV1, and not advanced consisting addresses in CV19.  And the only way to deactivate an advanced consisting address is to program a 0 into CV19.

This begs the question - how can E-Z Command deactivate a long address when reprogramming a decoder that has a long address?  It does so by always clearing bit 5 of CV29 when it sets a short address.  That is, it subtracts 32 from the value in CV29 if the value in CV29 is greater than 31.  The long address is left as is in CV17 and CV18, but without a 1 in bit 5 of CV29, the decoder knows not to use it. 

Jim   

[boomertom]

My question is this - is an address set on a Bachmann system to let us say 4 equivalent to an address of 0004 set on a Digitrax or other similar system?

/quote]

Jim,

Do I correctly understand then that a Bachmann address of 4 would equate to an address of 04 on Digitrax?

I am becoming more involved in a modular group which uses Digitrax and would like to be able to run locomotives in both universes without continual reprograming.

Tom

[Jim Banner]

Yes.  Bachmann 4 is equal to Digitrax 04.

Jim