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nce wireless protocol - how does it work?

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  • Member since
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  • From: lavale, md
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nce wireless protocol - how does it work?
Posted by gregc on Monday, July 15, 2013 6:01 PM

trying to understand why it doesn't work so well at a club.   Plan on borrowing a spectrum analyzer from work to check for interference.   Found a hackers guide, that provides some info on frequency and how to improve radio performance of base.

info on antenna in cab? interested in knowing if separate freq are used for tx and rx, assuming it's duplex and   how cabs would know when to tx?

greg - Philadelphia & Reading / Reading

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Posted by maxman on Monday, July 15, 2013 6:06 PM

Do you have the latest base station, RB-02, or the original RB-01?  And do you have any repeaters?

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Posted by gregc on Monday, July 15, 2013 6:20 PM

don't know

greg - Philadelphia & Reading / Reading

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Posted by cacole on Monday, July 15, 2013 6:57 PM

Why don't you address your questions to NCE?   They answer emails and don't keep anything about their systems a secret, as near as I know.   The frequency or frequencies used would have to be those approved by the FCC.

They also have a complete technical document archive available for download.

I'm not sure what you mean when you say it doesn't work well at a club -- we have the NCE system with 12 radio throttles and 3 receiving antennas at our large HO club layout (20 x 40 foot room and a 20 x 15 foot secondary room) and we have no problems with reception.  If your club is having problems, perhaps they have two throttles set to the same frequency.  The NCE radio throttle instructions explain in detail how to change frequencies and which frequencies are allowed.

Before anyone can offer useful advice, we need to know EXACTLY what your club has -- PowerHouse Pro with which EPROM Version Number?  Has the club ever purchased and installed an upgrade?  How many receiving antennas?  If more than one antenna, where are they located?  How many radio throttles?  Configuration of the layout (room size).  Any other electronics devices that could interfere with reception?  A diagram would be helpful.

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Posted by richhotrain on Tuesday, July 16, 2013 10:10 PM

Call Larry at NCE.  He knows all of that stuff.

Rich

Alton Junction

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Posted by cuyama on Tuesday, July 16, 2013 10:16 PM

Call NCE. Days spent conjecturing about what's occurring will likely just delay the eventual resolution.

By the way, if you don't have the latest firmware installed, that would be the very first step. And for that, again, call NCE

There are a number of club and club-sized home layouts with many throttles using NCE wireless in this area with zero trouble. But that is using the latest firmware -- and with repeaters in the largest cases. 

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Posted by mlehman on Wednesday, July 17, 2013 3:46 PM

Yeah, if you don't have the update for the RB02 from a few years back, you can and likely will have problems. Since NCE did the update, performance has been all but flawless on my system.

If the problems just started lately (presuming the system has the update), figure out what changed. Did the base antenna get hit or changed? Is the repeater still connected properly? Etc.

IIRC, the mode used is some sort of spread spectrum and may not show much on a conventional spectrum analyzer???

The only useful hacks I've seen that are ones to let you ditch the external antenna and rely on an internal one on the older design cabs. That will reduce performance slightly at the edge of effective range, so not something that will make much difference for whatever is ailing you.

If simple and obvious doesn't solve your problem, call NCE as others have advised

Mike Lehman

Urbana, IL

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Posted by gregc on Saturday, July 20, 2013 3:34 PM

cacole
Why don't you address your questions to NCE?

spoke to nce.  This is what i learned

  • the wireless base (and I assume their cab-bus) polls each cab and waits for a response before polling the next possible cab
  • LEDs indicate activity and there is infrequent activity when no handhelds are active
  • the wireless system therefore needs only a single frequency and does not use an spread spectrum technology
  • they use 916.5 MHz which is a in the T-GSM-900 cellular band which may cause interference
  • the base and repeaters transmit simultaneously
  • they said to use version 2.0 or better if the second repeater port, B, is used
  • they use a monopole antenna on the base and a small ground plane on the printed circuit card
  • there are large layouts successfully using the nce wireless system

Larry was very helpful and patient with all my questions

greg - Philadelphia & Reading / Reading

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Posted by richhotrain on Saturday, July 20, 2013 6:54 PM

gregc

cacole
Why don't you address your questions to NCE?

spoke to nce. 

Larry was very helpful and patient with all my questions

Good to hear.  Yep, Larry is a gem.

Rich

Alton Junction

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Posted by Stevert on Saturday, July 20, 2013 10:24 PM

Greg,

  In addition to the info you got from NCE, you may want to pose your question, along with a list of the symptoms, on the NCE Yahoo! list.

  There are folks there with lots of real-world experience with issues such as yours who can provide guidance and offer suggestions.

http://groups.yahoo.com/group/NCE-DCC/

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Posted by mlehman on Monday, July 22, 2013 4:27 AM

gregc
the wireless system therefore needs only a single frequency and does not use an spread spectrum technology

greg,

Do you recall if Larry mentioned what mode the emission was? Sounds like maybe TDMA?

http://en.wikipedia.org/wiki/Time_division_multiple_access

Mike Lehman

Urbana, IL

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Posted by gregc on Monday, July 22, 2013 5:05 AM

my understanding of TDMA is that there is simultaneous transmission in each direction and a timeslot for each device

the NCE system is half-duplex, transmission occurs at one frequency and only one device (master or any one cab) transmits at a time.   The master polls each cab, stops transmitting and waits for a response from that cab, and then repeats the sequence for the next cab.

greg - Philadelphia & Reading / Reading

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Posted by rrinker on Monday, July 22, 2013 6:31 AM

 Yes, it sounds to me like the NCE radio system doesn;t have any sort of multiple access since the cabs are polled one by one. More of a token passing system than a multiple access system.

 That constant polling from the base is why the NCE radio swamps any nearby Digitrax simplex radio system, they are on the same frequency and the NCE system never shuts up. In any multiple club display venue, any Digitrax layouts that want to run radio have to use the duplex system with is on 2.4GHz.

          --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by richhotrain on Monday, July 22, 2013 7:01 AM

Man, I gotta tell ya, if I need to understand all of this stuff, I am going back to DC.   LaughLaughLaugh

Rich

Alton Junction

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Posted by zstripe on Monday, July 22, 2013 7:46 AM

richhotrain

Man, I gotta tell ya, if I need to understand all of this stuff, I am going back to DC.   LaughLaughLaugh

Rich

Rich,

Naw,Naw,,,Stay with DCC,,You have too many reverse loops on your layout!! Being as how I'm strictly DC,,I avoid them,like the ''Plague''...

Cheers,

Frank

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