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replacement for UTP

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  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Friday, March 16, 2018 2:47 PM

 Are you sure it's truly wired in parallel? That's the only caution I'd have for soem random device as opposed to one made for model railroad use. A phone doesn't care if the pins are flipped - the cab bus power and signals do.

                                         --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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  • From: lavale, md
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Posted by gregc on Saturday, March 17, 2018 8:21 AM

polarity doesn't matter for tip/ring phonesd.  But these are RJ-45 jacks that are used for other interfaces (DCP, ISDN, Ethernet, ...) that have standard wiring plans.

rrinker
Are you sure it's truly wired in parallel?

a different listing (also $8) provides the following

    

this thread is mostly a question about how the NCE cabbus works (which I'm curious about).   I am considering using these for a serial bus connecting Arduinos togther and possibly provide power.

greg - Philadelphia & Reading / Reading

  • Member since
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  • From: Reading, PA
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Posted by rrinker on Saturday, March 17, 2018 11:45 AM

Edit: Unless the schematic is showing one side upside down (doubtful) those are wired as crossover when you go left to right, but the two on the left and the two on the right are correctly wired in parallel. Let's say the way it's drawn, the tab on the plug goes up. Pin to the top, to the left of the tab, is pin 1 if plugging in to the upper left socket. Now unplug from there and plug in to the top right connector - the wire to the left of the tab is now on pin 6. 

Edit 2: Looking at the board layout, they ARE flipped correctly. So which is is, the board layout, or the schematic? They don't agree with each other. One is correct, one is not.

 With only 6 wires they aren't RJ45.

6 wires are used by both NCE and Digitrax to carry both signal and power. In the case of NCE, 2 pins aren't even used except for the PowerCab as a way to get track poower from built in booster back to the panel. Digitrax uses the center pair for the data + side, linked together in every throttle, and the extra 2 are both grounds.

 With 4 pairs in RJ45, you could use two pair for power (doubling the effective wire size) and still have full duplex communications with one pair for TX and the other for RX of the data. I'm using RJ45 to interconnect the bits of my control system, mostly to allow more grounds but also to keep it distinct from the 6 pin Digitrax wiring. The bus for the RS485 I may go with shielded cable and screw terminals on the boards. Signals I may end up using 10 pin ribbon cable like other signal systems because that gets me all 8 bits of a port plus power and ground. I'm undecided if i want to multiplex the signal drives and save ports or just keep it simple with one bit per LED - the IO expander chips are so cheap. The tradeoff between more ports and more complex circuit leans towards more ports being the cheaper option. Keeps the firmware simpler, too.

                                         --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    July 2009
  • From: lavale, md
  • 4,642 posts
Posted by gregc on Saturday, March 17, 2018 12:30 PM

rrinker
Edit 2: Looking at the board layout, they ARE flipped correctly. So which is is, the board layout, or the schematic? They don't agree with each other. One is correct, one is not.

not sure what you're looking at.    

the connectors are all oriented the same way, tab is in the same direction for all four (i don't see any flipped).  The schematic connects together the top left pin of each connector.

rrinker
With only 6 wires they aren't RJ45.

yes you're right, RJ12.  i've been looking at both.

i ordered some single socket boards with screw terminals to extend my cabbus and i've ordered one of these 4-way bridges to connect my Arduinos together.

 

greg - Philadelphia & Reading / Reading

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Posted by SouthPenn on Saturday, March 17, 2018 1:22 PM

Why don't you forget all the wiring and go to radio control? 

South Penn
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  • From: lavale, md
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Posted by gregc on Saturday, March 17, 2018 1:24 PM

i don't even need walk-around.   i do RF at work

greg - Philadelphia & Reading / Reading

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  • From: Reading, PA
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Posted by rrinker on Saturday, March 17, 2018 1:39 PM

The orientation on the board layout was not clear. I was assuming the open ends of the sockets faced left and right. If they are facing up, then it appears to be ok. Nearly everything I've ever built with RJ jacks on pc boards uses right angle types in which case you would want the connections to not be straight across, that would connect 1 to 6, 2 to 5, etc. 

                                   --Randy


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    November 2005
  • From: Phoenix, AZ
  • 693 posts
Posted by woodone on Saturday, March 17, 2018 1:46 PM

To me this sounds like the guy who drove 50 miles to save 2 cents a gallon on gas.

Guess I would just buy the panel from NCE and be done! 

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  • From: Bedford, MA, USA
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Posted by MisterBeasley on Saturday, March 17, 2018 2:23 PM

I've got a Lenz system that uses DIN-5 plugs and jacks.  When I built my layout, I put a bunch of jacks all around the layout, about 9 or 10 in all.  I just bought the jacks, drilled holes in the fascia and wired them up.  The jacks cost a dollar or two each.  The system works great and I'm never at a loss for where to plug a throttle in.

To buy pre-made panels with jacks is $36 each.  I like my do-it-myself system.

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Saturday, March 17, 2018 5:57 PM

 Just ask MRC what their problem is. RJ12 (really there is no such thing - ir's an RJ11 6p/6c) is not all that common - our old analog office phone system used them but that was replaced many years ago, yet NCE and Digitrax panels are much less expensive than MRC's, which use common as dirt RJ45 jacks - everyone uses ethernet cables. 

 DIY is possible with the any of them. The pinouts for NCE and Digitrax are both readily available. The main difference between the two is where the power comes from - at one time, perhaps they still do, Tony's had generic UP panels you could use with either system, except that it then required a battery in the Digitrax throttles because the Railsync lines which carry the power on Digitrax were not used - Railsync is on the outermost pins of the connector, which are not connected for standard NCE cabs - only the PowerCab uses those wires.

                              --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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