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Loconet cable wiring

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  • Member since
    January 2005
  • From: Winnipeg Canada
  • 1,637 posts
Loconet cable wiring
Posted by Blind Bruce on Saturday, November 1, 2008 10:11 AM

`Since I can't find a "search" button on this new fangled website, I need to ask a question that has been answered many times before.

When attaching the RJ12 plugs to a cable, are they reversed or straight through? I think I need a pictureEight BallGrumpy

73

Bruce in the Peg

  • Member since
    July 2008
  • 1,206 posts
Posted by mfm37 on Saturday, November 1, 2008 10:36 AM

 Straight through. Pin one to pin one. Convention is to have the blue wire on pin 1. As long as they are the same on both ends, that's OK.
 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Saturday, November 1, 2008 11:55 AM

 Easy way to tell - If you lay the wire out flat, one connector will have the tab up, and the other the tab down. Telephone wiring is reversed, so if you lay a telephone wire out flat, both ends will have the tab up.

 Here's the relevent section of the Digitrax tech support site: http://www.digitrax.com/kb/index.php?a=365  (maybe it links right to the article)

 The kicker - it actually doesn't matter UNLESS you have more than one booster. If the cable between two boosters is made telephone style, the two will be out of phase and you'll wonder why the breaker trips every time a train crosses the gap between the two power districts. The right thing to do is make all the cables the right way so this issue never comes up. But if you should happen to run a backwards one from the command station to a UP5, and then plug in a throttle - it will still work.

 Kicker #2 - there was a batch of DB150's made at one time that have the rail outputs wired backwards (What is Rail A on the affected units is what normally is Rail B, and vice-versa). If you wire that in with a CORRECT loconet cable - you'll have the problem above. You can either make a cross (phone style) cable for it - and LABEL IT CLEARLY) or flip the track connections, ie if your RED bus normally connects to Rail A, connect it to RAIL B on the 'backwards' booster, and use a normal Loconet cable.

                                     --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
    August 2005
  • From: Austin, TX
  • 1,752 posts
Posted by Don Z on Saturday, November 1, 2008 11:48 PM

Blind Bruce

`Since I can't find a "search" button on this new fangled website, I need to ask a question that has been answered many times before.

Bruce,

Look for the red arrow in the photo to locate the "Search" button:

Don Z.

  • Member since
    January 2007
  • 327 posts
Posted by locoworks on Sunday, November 2, 2008 9:02 AM

rrinker

 Easy way to tell - If you lay the wire out flat, one connector will have the tab up, and the other the tab down. Telephone wiring is reversed, so if you lay a telephone wire out flat, both ends will have the tab up.

 Here's the relevent section of the Digitrax tech support site: http://www.digitrax.com/kb/index.php?a=365  (maybe it links right to the article)

 Kicker #2 - there was a batch of DB150's made at one time that have the rail outputs wired backwards (What is Rail A on the affected units is what normally is Rail B, and vice-versa). If you wire that in with a CORRECT loconet cable - you'll have the problem above. You can either make a cross (phone style) cable for it - and LABEL IT CLEARLY) or flip the track connections, ie if your RED bus normally connects to Rail A, connect it to RAIL B on the 'backwards' booster, and use a normal Loconet cable.

                                     --Randy

 

i had an issue with this i think??  i have a UR91 that works fine with my chief system, but when i plugged it into my empire builder system, the lights flashed on the UR91 to say it was getting a radio signmal, but nothing would move, swapping out the loconet cable for a crossover one cured the problem on the empire builder, but then it wouldn't work with the chief. depending on which system is in use depends on which cable i need to use??

 

 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Sunday, November 2, 2008 11:38 AM

 It shouldn't matter - you should always use a straight cable, and they should always work. Certain devices actually connect the center two pins (Loconet signal) and the next two (pins 2 and 5) together (Loconet Ground). On the command station, only 1 of the Loconet signals is actually connected. Plugging in a throttle connects the two - you can see this if you still have your LT-1 Loconet tester. Jus tplugging it in, NOTHIGN else, and only 3 of the 4 LEDs will light, Plug a throttel into the other Loconet port and all 4 LEDs will light. If you happen to ahev an extra throttle besides your radio unit, if you use the straight cable on the DB150, or the crossover on the DCS100 (the ways it DOESN'T work), and plug in the second throttle to the other Loconet port on the command station, I'll bet the radio works. You can make a 'jumper plug' to connect anywhere ont he entwork to tie the wires together. Use a short section of 6-wire cable, crimp a plug on one end. At the other end, strip the wires back. Cut off the outer two - pins 1 and 6. This is the Railsync and these cannot be allowed to short together. The next innermost pair, pins 2 and 5, are the ground, connect those together. And then the center pair, the Loconet signal, connect those together.

 Here's a bit of a reference from Allan Gartner's Wiring for DCC site: http://www.wiringfordcc.com/booster.htm

 

                             --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 2008
  • 1,206 posts
Posted by mfm37 on Sunday, November 2, 2008 4:15 PM

 It's not limited to some DB150's. We've got two DCS200's, a DB200, and DB150 for club use. One of those DCS200's is reverse phased to the rest since day one. This despite the fact that the two DCS200's were ordered and arrived at the dealer from Digitrax on the same day. We use the reversed DCS as the command station. One single well marked telco style cable runs from it to an LNRP. From there all  cables  are straight through data style. We have 1000 feet of loconet cables and check each one before use. Bad plugs wreak havoc on run day so it's always best to double check those cables.

Martin Myers 

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