DCC Question

I understand the concept that the 'instructions' to the locomotives etc. are carried along the AC powered trackwork, my query however is this:- If you instruct 'Loco A' to travel in a certain direction at a certain speed, it will do this until it receives an instruction to the contrary. What happens if the power is interrupted ? When the power is restored, will the locomotive pick up again from where it left off, or do you have to re-programme it all again ?

Reply to
Keith J Patrick
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In DCC, "programming" refers to setting up the CVs to define how the loco behaves, e.g., maximum speed, etc. This programming is retained even when there is no power.

When operating, the command station continually refreshes the instructions to all the locos on the track so each loco is regularly being instructed to travel in a certain direction at a certain speed. If the loco has a momentary power loss due to dirty track or a short circuit then it may just carry on going as before. If the power loss is long enough to cause the decoder to reset then it will wait for the next packet addressed to it. Either way you shouldn't see much effect due to the rate at which packets are repeated.

The Lenz power-1 module is designed to overcome really bad power loss by using a capacitor to store enough energy to keep the decoder alive and actually power the motor for a brief but noticeable period.

If a loco doesn't see a packet addressed to itself for an extended period then it can switch to analogue mode and run away. It's best to disable that feature unless you really need it.

Andrew

Reply to
google

In message , Keith J Patrick writes

A quick quibble on terms Patrick, programming is the process of setting the CVs in the Decoder (everything from the loco address to the different settings in speed tables)

If a loco is running and the power is interrupted then you will have to issue instructions to loco once the power is restored. If the loco stops because of a momentary interruption (dirt or suchlike) it may resume its previous action.

Reply to
Ian Birchenough

On 5 Jul 2006 09:01:04 -0700, snipped-for-privacy@sheerstock.fsnet.co.uk said in :

that's a good idea, mine are forever stopping.

Guy

Reply to
Just zis Guy, you know?

OK, take it one stage further! Suppose you have say, a dozen storage sidings on a layout controlled by DCC. I assume then, when you 'park' a train in one of those you have to 'turn it off', and then 'recall' it when you want to run it again ? What if you want to have some form of automatic feed of trains coming onto the layout ? This would be relatively easy on straight DC, but I am struggling with the concept of doing it in DCC.

Reply to
Keith J Patrick

I have a Lenz set 100, If I press the emergency stop button (or there is a short), trains that had a command will re-start. The locomotive is programmed on a programing track and the whole system remembers the identity of each loco. The memory is not volatile to that degree. Hope this helps, Steve

Reply to
titans

In message , Keith J Patrick writes

When you bring your train into the storage sidings and you set its speed to zero it halts - if you want to you can then deactivate any functions running on that train (Carriage lighting, sound etc.). You can then change the points to allow a train on an adjacent siding to proceed. You call up its address and increase its speed (setting any additional functions you are using) to extract it from the sidings. If you have a capable command station or a computer interface you can set a route, triggering all the points (and signals) along the way. Decoder Pro and Panel Pro from JMRI will do this for you.

As to automating the dispatch and receipt of trains from your fiddle yard, I would have thought this is relatively simple as long as you always want the same train in the same siding. Someone better than me would be able to give you a definitive answer.

Might I suggest you ask at: snipped-for-privacy@yahoogroups.com or snipped-for-privacy@yahoogroups.com

both are subscription newsletters but you'll get one or more methods of achieving your aim. What DCC system are you using (or planning to use)?

Reply to
Ian Birchenough

When you park your train with DCC you just set the speed to zero. All of the track (and thus locos) remain powered. The loco just sits there waiting for a new instruction. In the meantime you can use the throttle to control another loco. When you want to run the loco again, just select its address on the throttle and turn up the speed.

In DC you could park the loco simply by killing the power to the siding and turning it on again when you want the loco to move, maybe using the points to switch the power. All this could be controlled by relays and simple sensors, Is that what you mean?

DCC is much more sophisticated and you have to instruct each loco individually. For true automation, you really need a computer connected to the layout. Some decoders will allow some degree of automation. One common method is by sensing DC applied to the track (instead of the DCC signal) and stopping. In that case you have no control over lighting or sound functions. There are proprietary methods, that retain function control, such as Lenz ABC which alters the voltage of the DCC signal during one phase to send signalling information to the decoder.

Andrew

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google

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