I need to decide if I want to use the Keep-Alive decoders and give up the automated stopping for my hidden staging tracks since the KA decoders will ignore the track power being cut.
Is it either/or? Anybody come up with a trick that allows both?
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Once I had put a keep alive in a few locomotives, I was hooked. I have one in all of my locos now and will not run a sound equipped loco without one.
As to the automated stopping issue; lengthen the dead spot a bit and use big soft open cell foam bumpers maybe?
Yep, you can't have your cake and eat it too ....
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Well, if you use decoders that support things like Asymmetrical DCC for stopping, they will stop, becuase it's a programmed response in the decoder, not just cutting power.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
carl425 Is it either/or? Anybody come up with a trick that allows both?
That's an interesting question...
You can program decoders with analog (alternate) power disabled.
There is also a CV parameter which is a timeout for a valid DCC packet. If not valid DCC packet is found within so many ms, then the train auto stops at the programmed deceleration rate in CV4.
Now here's the trick...put in a block detector and a DPDT Relay. When the engine passes a certain section, switch the entire block to DC from DCC. This will keep the engine alive and allow it to stop automatically when the DCC packet times out.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Carl,
I don't know about automated stopping but my experience with the Keep Alives is that as soon as they detect the power loss there is a distinct slowing depending on the speed step. The KA 1 will travel only a short distance and the KA 2 and Soundtraxx circuit keeper will travel maybe six or eight inches before stopping regardless of the momentum setting. You might want to experiment with one first before trying somthing electronically elaborate. It may not be a problem.
I have Keep Alive capability in all my engines and am sold on how much they have improved the way the engines run.
Marty C
Stop on DC should also stop - not keep going until the keep alive runs out of power. Again, it's a command (or lack thereof) tot eh decoder that makes it shut off the motor output, not a loss of power.
The asymmetrical DCC is much more versatile though. But not all decoders support it yet.
The only thing that will not work properly with a keep alive is the old trick of the end of the track being insulated and connected to the rest via a normally open pushbutton. The keep alive will keep the loco moving for a while after is passes the gap, even if you aren't holding down the button. That's not a great idea for DCC anyway, unless you can actually see the end of the track - if you have 2 or 3 powered units in consist and run into such track, and aren;t watching what's going on, when the first loco hits the gap it will stop, and the other will keep on pushing since it's still in front of the gap. Depending on the train, that second unit might not be able to push the dead one AND pull the rest of the train, so if you aren;t paying attention it can just be sitting there spinning - not a good thing.
rrinkerThe only thing that will not work properly with a keep alive is the old trick of the end of the track being insulated and connected to the rest via a normally open pushbutton.
My original plan, before becoming enamored with Keep-Alive, was to use the RR-cirkits detection and relay boards to cut the power to the whole block when the train trips an optical detector. This then allows power to be restored using a DCC switch command - probably as part of a route. An added benefit is not having power on the staging tracks where trains are parked.
Simple solution - instead of just cutting power with the relay, look at the DCC Bitswitch. Instead of DCC/nothing, you'd wire the relay up to send either DCC or the output of the Bitswitch - which can sit there and broadcast stop commands. Since these are stop commands, same as turning the throttle to stop, the keep alive will have no effect. Train will stop, and if you issue a command to switch the relay, you're back in business with regular DCC to the loco.
rrinker Simple solution - instead of just cutting power with the relay, look at the DCC Bitswitch. Instead of DCC/nothing, you'd wire the relay up to send either DCC or the output of the Bitswitch - which can sit there and broadcast stop commands. Since these are stop commands, same as turning the throttle to stop, the keep alive will have no effect. Train will stop, and if you issue a command to switch the relay, you're back in business with regular DCC to the loco. --Randy
Cool! Might get pricey though with an $80 board and an extra booster.
carl425 rrinker Simple solution - instead of just cutting power with the relay, look at the DCC Bitswitch. Instead of DCC/nothing, you'd wire the relay up to send either DCC or the output of the Bitswitch - which can sit there and broadcast stop commands. Since these are stop commands, same as turning the throttle to stop, the keep alive will have no effect. Train will stop, and if you issue a command to switch the relay, you're back in business with regular DCC to the loco. --Randy Cool! Might get pricey though with an $80 board and an extra booster.
What command station do you have? The reason I ask is because the Digitrax DCS100 (Super Chief) can be configured to output the broadcast set speed zero packet on it's programming outputs. You would still need another booster (the $50 one from Tam Valley Depot should work fine), but you wouldn't need the separate break generator.
There is a possible issue with this solution; however. This works by sending a set speed zero to the broadcast address (primary or short address '0'). ALL decoders are SUPPOSED to respond to this address, but at least some MRC decoders do not. As long as you don't have any MRC decoders, this option should work fine.
CSX RobertWhat command station do you have?
I have the DCS200. So I could accomplish the scenario Randy describes with the DCS100 as the 2nd booster and not require the BitSwitch? Can you point me to a document that I can use for instructions?
CSX RobertAs long as you don't have any MRC decoders, this option should work fine.
I have no MRC decoders.
KB331: Brake District Set-Up using DSC 100 and a second booster.
CSX Robert KB331: Brake District Set-Up using DSC 100 and a second booster.
Thanks!