Just end it. Wire nut would be good.
Right. And it's a perfectly good question.
It takes an iron man to play with a toy iron horse.
Just to add a bit to the previous responses, since - Terminate each of the bus wires individually! Don't tie them together or anything like that...
Like it has already been said just cap the ends off however you see fit. Do not cap them off together and DO NOT loop them back to the command station. This causes the signals to leave the command station in 2 different directions and arrive some times to the device at different times causing confusion in the device and also if the command station gets feedback throug the track bus then those signals would also return to command station at different times. The times we are talking about are miliseconds but if the offset is right that could turn a 1 into a 0 or visa-versa.
Massey
A Veteran, whether active duty, retired, national guard, or reserve, is someone who, at one point in his or her life, wrote a blank check made payable to "The United States of America" for an amount of "up to and including my life."
SMassey Like it has already been said just cap the ends off however you see fit. Do not cap them off together and DO NOT loop them back to the command station. This causes the signals to leave the command station in 2 different directions and arrive some times to the device at different times causing confusion in the device and also if the command station gets feedback throug the track bus then those signals would also return to command station at different times. The times we are talking about are miliseconds but if the offset is right that could turn a 1 into a 0 or visa-versa. Massey
Actually there seems to be a different opinion on this question. See the following link http://www.wiringfordcc.com/track_2.htm#problem_blown. Should take you to a section called blown decoders (unterminated bus ends). If you scroll down aways you'll see a simple connecting circuit.
I am not saying this is necessary, or that it applies to OPs question, or that it actually means diddly. I'm only pointing it out because I happen to have read it one time.
Regards
SMassey DO NOT loop them back to the command station.
You shouldn't loop a throttle bus, but it's perfectly acceptable to loop the track bus. Proof is in all the oval/circle/otherwise looped layouts operating just fine.
maxman Actually there seems to be a different opinion on this question. See the following link http://www.wiringfordcc.com/track_2.htm#problem_blown. Should take you to a section called blown decoders (unterminated bus ends). If you scroll down aways you'll see a simple connecting circuit. I am not saying this is necessary, or that it applies to OPs question, or that it actually means diddly. I'm only pointing it out because I happen to have read it one time. Regards
The "ringing" described in that writeup, and addressed by the bus termination circuits described there, usually only affect bus runs of about 30 feet or more, and it seems to affect some DCC systems more than others.
For example, my longest bus run is about 22 - 24 feet, and I've never experienced any of the blown decoder or erratic operation effects that are symptomatic of bus ringing.
So many users will not need to add those terminator/snubber circuits. But on the other hand, they probably won't hurt, either, so if you think they may resolve an issue you're seeing go ahead and add them.
Thank you for the correction, yes the thottle bus is what I ment. The track bus is usually a loop anyway in some cases.
Using an RF filter on the ends of the bus wires would help eliminate any stray RF that the bus would pick up. Using a capacitor in the circuit you dont actually create a short but it will allow any stray voltages to be eaten up by the resistor with out effecting the main supply current. I like the idea. I need to find a scope and check my layout out and see what it's waveform looks like. I have 3 power districts and one reversing section I imagine that there may be some stray RF on my rails.
I've never had an issue with the ends of my bus wire just tied together (in a knot, to the last tie-down, NOT electrically, that would be a short). No use of a snubber circuit or anything. My layout's only about 10x15 though. However, the club modular layout is over 100 feet long when all modules are used, and we have no snubbers there either, and there are no issue with loss of control or worse, it all works just fine. The snummber circuit and the need for bus termination seems mostly needed for NCE PowerPro systems, they constantly talk about it on their Yahoo group.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Huh? Track bus is NOT a loop! What is a throttle bus? Digitrax loconet perhaps?
Dean
30 years 1:1 Canadian Pacific.....now switching in HO
mactier_hogger What is a throttle bus? Digitrax loconet perhaps?
What is a throttle bus? Digitrax loconet perhaps?
A throttle bus is simply the mechanism by which DCC devices within a given architecture communicate with each other.
So yes, Digitrax's LocoNet is one type of throttle bus, but it's certainly not the only one. NCE throttles/devices plug into an NCE throttle bus, Lenz throttles/devices plug into an Lenz throttle bus, and so on...
Thanks for that! I'm guessing that that shouldn't loop either?
From reading the documentation that comes with the Lenz system, I learned that the throttle bus should be terminated with a resistor. They even supply the appropriate resistor. So, when I added a long throttle bus and a bunch of jacks and it didn't work, I knew pretty quickly what step I'd left out.
Note that this is a Lenz system. Different rules apply in different sports, so you may not want to do this with a different brand.
Loconet should NEVER loop back on itself. For one thing, if the proper cables are used, looping it back on itself will actually cause a dead short on the Railsync pair of wires.
The track bus - it doesn't matter. If it mattered, a basic oval layout would never work on DCC because guess what, it loops back on itself! Now, it is completley unecessary and a waste to run bus wires BACK from the far end of a linear layotu just to close the loop, that serves no purpose other than to waste wire. But if your layotu is round and not too large, unless you split the track with insulated joiners it doesn't matter if the bus completes a circle or not, the track it's connected to does. On a larger looping layout, say around the walls of a room, the best way to arrange the bus wires is to go equally around in each direction, keeping the distance from the power source to a minimum by having it in the middle of the overall bus run.. On a REALLY bg layout, say the bus run woudl be 150 feet, it's usually best to distribute the boosters, in this case 50 feet from each end, that would make the maximum distance from any booster no more than 50 feet, and of course the bus would be NOT conected between the two sections, plus the track needs to be double gapped at that point as well.
--50 ft --- booster 1 -----50 ft ------||-------50ft-----booster 2----50ft----
like that.
BobL609How do I terminate the bus wiring....does it just end and you put a wire nut on it, does it have to be looped back on itself? I apologize for these questions but when I went to college all the electrical engineering courses were full so I ended up in business administration.
I just attached my last pair of feeder wires to the ends of the bus.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
For the track bus, I'd crimp a ring lug on each wire, then screw each in turn to the nearest wooden structural member. About an inch of separation between wires ought to do it.
I used to be clueless, but i've turned that around 360 degrees.
Not clear on the terminology TRACK BUS vs. THROTTLE BUS
I have a very small, very basic layout, that matches my knowledge of DCC - very basic. In this past December I just upgraded from DC to DCC with the NCE Power Cab. I only run 2-3 locos at one time, so this small 2 amp system works fine. Plus if I need to expand capacity, there is a 5 amp booster available that will be compatible with the cab controller. My knowledge of DCC is very basic. The NCE Power Cab is great, the instructions to get started and how to wire were very clear and it was easy to install and wire. Enough with the background, here is my question, in getting familiar with DCC and NCE Power Cab - I did understand the terminology of a bus that you run feeders off of to the tracks - but don't understand the terminology throttle bus vs. track bus – is the track bus the bus supplying the main feed from the DCC power panel to the tracks? Since I have wired only one bus from the NCE DCC power panel and run feeders from this bus to the tracks I am thinking this is a TRACK BUS. If so, what is a THROTTLE BUS? And what purpose does it serve? With a basic system and only a single tethered cab controller, I am guessing that I do not need to consider a THROTTLE BUS. Pardon my basic and dumb questions, just trying to learn the ropes and terms, thanks
sysout10 Since I have wired only one bus from the NCE DCC power panel and run feeders from this bus to the tracks I am thinking this is a TRACK BUS. If so, what is a THROTTLE BUS? And what purpose does it serve? With a basic system and only a single tethered cab controller, I am guessing that I do not need to consider a THROTTLE BUS. Pardon my basic and dumb questions, just trying to learn the ropes and terms, thanks
Since I have wired only one bus from the NCE DCC power panel and run feeders from this bus to the tracks I am thinking this is a TRACK BUS. If so, what is a THROTTLE BUS? And what purpose does it serve? With a basic system and only a single tethered cab controller, I am guessing that I do not need to consider a THROTTLE BUS. Pardon my basic and dumb questions, just trying to learn the ropes and terms, thanks
Yes, the pair of wires that goes around your layout and to which you attach the track feeders is the track (or power) bus.
Your PowerCab plugs into a PCP panel. The transformer plugs into the back of the PCP. The track bus wires also attach into the back of the PCP.
If you acquire another throttle, you can plug that into the right side socket of the PCP. The PowerCab has to stay connected to the PCP. But lets say that you would like to walk to the other side of your railroad and operate from there with the additional throttle. At that location, you would install a UTP panel. These look similar to the PCP, except that there is not connection to the track, nor any power input for the PowerCab. You would run a connection from the back of the UTP to the back of the PCP. You could add additional UTPs if you wanted to and they would daisy chain from one to the other. That would be the throttle bus.
thanks maxman, really appreciate your reply, clears up my confusion - and it is making me think of adding an additional throttle and having a second location with a UTP - with the tethered 6 foot cord, I have a section of the layout where I like to view and control from, but too far away from the PCP - thanks again, now I have a good idea on how to add this second UTP location
There are many different wiring situations and so it is easy to see where the confusion comes from.
With old computer networks it was necessary to put a device at each end of the coaxial cable to terminate it properly.
With old 300 ohm flat TV antenna wire a length that was not used but just left hanging (maybe the TV was moved) would paint ghosts on the other TV sets on the system. You had to remove such a cable at your junction for the other sets to work correctly.
The more wire you have the more gremlins you will have. I had some problems with the neutral wire on my layout, once it was grounded to a hard ground the stray signals went away.
We just installed a new gas boiler (a stand-by in case the coal boiler failed in the winter, of for use in the summer when we service the coal plant). In any event, it shut down on low water, and it took our engineer a while to find the issue. The pump room had a circuit breaker that went out, but the issue was a loose wire on the other boiler, a wire that the electrician thought was dead, and so he did not cap it. oops.
Know the RIGHT way to wire before you devise any shortcuts that you may want to use.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS