Perhaps this subject has been previously addressed here. But while I'm at it: Exactly WHY is it necessary to isolate and/or have a separate track to "program" a new address? I am looking at the diagram in my Digitrax manual. I also have a common electrical switch that has two screw-posts for connecting each end of a "hot" wire that has been cut. The switch turns on/off power to the main track(s); while the "program" track remains powered on at all times. Can't I simply put any loco - one-at-a-time - on the main tracks and program a new address? Or is it necessary - and WHY - to electrically isolate a separate "program track"?
Now...I'm going to go back and review previous posts to see if this issue was already addressed. Thanks.
G' Flash
What digitrax system do you have?. With the Zphyer and chief you need a programming track for addressing. With the Empire Builder programming is done on the main as long as you remove all other locos only for addressing. CV's can be adjusted on the main with the three.
The programming track has two major advantages. The first one has already been mentioned: When you program an address on the main, you program the address of every locomotive on your layout. When you've only got 2 or 3 engines, it's not such a big deal to remove all but the one you want to program, but when you're up to 10 or 20 locos, including big steamers that are a nuisance to re-rail, you don't want to be doing this a lot. Also, when you have highly-detailed models, you'll find that not handling them repeatedly is better for all those little grabs.
The programming track also provides protection. It does not use full power. So, if you mis-wire a decoder and try to program it, the program track will report an error. Then, you can go back and fix it. On the main, the same wiring error might let the magic smoke out of the decoder, and your investment might be good for a funny-looking gondola load, but not much more.
Sooner or later, you'll wire up a programming track. It might as well be now.
It takes an iron man to play with a toy iron horse.
Based on your description, you have a Super Empire Builder (DB150). You don;t NEED a programmign track, you can do exactly as you say, put one loco at a time on the track and program it. But one of these days you will slip up and forget to take the other locos off the track, and end up programming all of them.
You don;t NEED a programming track for the Zephyr or Super CHief (DCS100) either, but you can't read back CVs with those systems unless it's on the programming track. You can change the address in Ops Mode, I do so with my Zephyr all the time. I've even been able to change the default 2 digit address to another by selecting loco 00 and then using Ops Mode to program CV1. Typically though you cna only set a 4 digit address if the current address is a 2 digit one, and vice-versa.
Where a programming track (on the Zephyr and CHief) really comes in handy is testing new installs. Current on the program track is limited. If you inadvertabtly short out the decoder, or fail to properly isolate the motor, placing it on the program track won;t send enough current through it to fry it. It also won't read or write properly. So test on the program track before putting it on the full power main track. If it doesn;t work on the program track, STOP and check for wiring errors. Once it works on the program track, THEN test it on the main. You'll fry less decoders this way.
--Randy
Modeling the Reading Railroad in the 1950's
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