RailPro > RailPro Specific Help & Discussion
LM-4S-G Erratic behavior/Intermittent "Cannot Connect"
jordanhd87:
--- Quote from: Gibs on December 19, 2022, 10:05:53 AM ---I know that you stated that you keep your track clean, which I don't doubt. However there is another culprit.
When I look at that photo, I'm seeing a LOT of track, and the first thing that came to mind was, I hope hes using a Bloody BIG BUS system for that with plenty of droppers and more than one power supply. See the problem is the voltage that we use in model rail. Its bloody WEAK! By that I mean when it comes to long runs of cable and/or track, 12V-24V is pathetic to be a good POTENTIAL DIFFERENCE between POLES (+, -), even if its DCC. The longer the run the higher the voltage needs to be to get the job done plus the bigger the cable required. The funny thing is, the current can go DOWN when this is done. In fact it always does for the same given POWER (WATTS) Rating.
The other better option is to break the long runs down into practical lengths of Cable/Track runs. More power per given length with less loss.
So the question is, how long is a Powered section of the Track/Bus Run that you have per section, (I'm really hoping its in a lot of sections with a lot of droppers) and what size is your main cable bus.
Because if its not suitable for the length of your line, that may very well be your problem.
--- End quote ---
The loop is 300ft of track. It is all connected with railclamps, which have all been coated with NOALOX before clamping. Power supply is outputting 23.2 volts, it is 23.2 volts at every point of track including the farthest point away from the power supply. I only have one feeder going from the PS to the track. It is a short run (maybe 6 feet of wire or less?). I'll double check but I think I used 12/2 landscaping wire. My thought was, if I got power to the track with as short of a feeder as possible, the track itself is a bigger conductor than the feeder coming from the supply, therefore I'll reduce the drop. If I send feeders to the far sections, the wire I'd be using is a smaller conductor than the rail and I'd end up with bigger drops In the feeders than the rail itself.
Again, I have no issues with Revolution equipped locos or analog locos. No dropouts. No sudden stops. No slowdowns. Only ones I have an issue with are my Railpro locos. If what you suggest is an issue, I'd think I'd be experiencing it with Revolution and analog locos too. In addition, the issues I'm experiencing happen at any spot around my layout, not just the farthest spots.
JRad:
I think Gibs might have missed where you said Large Scale. I agree that brass code 332 track, if all connections are lossless, is a very good and large conductor.
You state that voltage is even around the layout. Might I suggest measuring the opposite side of the loop from the power connection when a train is running to prove there is no voltage drop.
I'm in Large Scale but got in before the LM-4 and am all battery power. Never a connection issue so long as loco is in range.
Gibs:
I get what you're saying in regards to the length of run from your power supply to the track its self, yes the shorter the better. The thing is, your BUS, it should be of a BIGGER Cross Sectional Squared Area than the Cross Sectional Squared area of your track. So looking at the track from the point of view where you see the cross section, the Bus Cable SHOULD be bigger by at least 2 x that surface area. I don't recall if you said you have Brass Track, but I still wouldn't rely on that alone myself personally to supply full power to such a largish track run.
Also relying solely on the track only, to supply the power around the entire layout, not a good idea, I'd be breaking that down into smaller sections with each sections own power supply. I know you state that all your other loco's run fine on the layout, but I'd be more inclined to call that a fluke. I'm thinking the other system may have onboard their circuit boards something akin to a Stay Alive, ergo a few extra capacitors to maintain power through bad sections of track.
The part that does my head in, is that you can repeat this fault inside on the test track at random intervals. Its like the Modules loose signal connectivity for some odd reason, normally I'd say all the above about your track layout and its suffering a small power loss at random moments given how its set up. The only thing I can suggest is add a suitable keep/stay/PMB Alive to one notoriously bad Loco and see if that makes any difference. I'd bet there is one available for G Scale somewhere.
Either that or just temp put a battery in.
PS: The reason I'm suggesting this, is to remove the possibility of a power issue from the equation. If its proven to not be a issue, then you have more information than before to tell Tim.
jordanhd87:
--- Quote from: JRad on December 19, 2022, 10:22:17 PM ---You state that voltage is even around the layout. Might I suggest measuring the opposite side of the loop from the power connection when a train is running to prove there is no voltage drop.
--- End quote ---
Thanks for your input. I do not get a warning triangle saying "low track voltage". In fact, the reading on each locomotives status page in railpro (while I have two to three locos running) shows about a 3 volt drop compared to the static track voltage. I obviously can't read this when the connection to the handheld drops out, but I can say the sound output in all cases continues loud and clear and does not crackle, drop out, or anything. I admittedly have not tested the track voltage with a meter with trains running to confirm the readings the railpro modules are putting out (I will do try that).
@Gibs - the track I am using is code 332 brass. In essence, the track itself is the BUS in this set up. As mentioned above, with the erratic behavior the sound always stays loud and clear and continues with no drop outs, indicating no loss of power below the threshold. Also I run a couple cars that pick up power for lighting - their power pickup is not nearly as robust as the locomotives, and they do not flicker or drop out around the layout either. I do wonder if an additional capacitor would help clean up the incoming power before it goes to the rail pro card though. But I recall Tim asking me if I had anything like that, and suggested that I shouldnt.
trainman605:
I have no answer to your problem, but think it's 99% your track power, intermittent voltage from the track probably effects the Rail Pro module to function as it should. If it works on battery power 100% of the time then you have your answer, just my personal thoughts on this. I know what I would do if I had a track powered layout outside, change to battery power and be done with it, no track cleaning and no track power connections to deal with.
trainman
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