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plasmadrive

Running LOR controllers when one data jack is bad

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I have been asked what to do if one of the RJ45 jacks on the controller goes bad.  I had that happen to two of mine last year in mid show.  These were not at the end of the data string so I had to feed thru to the next batch of controllers, no way out.

 

First I called LOR and they sent me new jacks after asking if I was comfortable to replace them.  Thank you LOR!

 

Secondly  I ran a short 6" cable to the good jack on the controller.  I connected it to an all female RJ45 "T" adapter.  (I had some of the RJ45 "T" adapters that I had purchased as a "just in case")
I then took the cable coming in from the previous controller and the one going out to the next controller and connected them to the "T".  Everything worked like a champ for the remainder of the season. 

 

As long as you keep the "stub" short it should work fine (in most cases).  I did not run this on a 500k network. This was on the regular 57k network.  I should work on the 500k network but I have not tried it. Keep the stub very short and remember to support the "T" so that you are not using the PCB RJ45 as a hanger.. you don't want that jack to go bad.

 

When the season is over, then replace the jack and you are good to go for the next year. (Oh yeah.. this is the hard part).

 

Having part around "just in case" is a good thing!

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Good info to know if my jacks ever get jacked-up.

(I know - sad - but I had too...lol.)

 

Nice tip.

Edited by Mega Arch

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Questionable terminology aside..... ;)

 

Using a 2-for-1 adapter like that can work in a pinch, however it is not recommended.  RS485 is great for sending a good amount of data out a long cable.  However one of the things it is very susceptible to are impedance mismatches and the signal reflections that happen because of them.

 

Signal reflections can wreak havoc across your entire display.  You won't damage anything, but you could be surprised to find 1 or 2 channels on a controller - or an entire network of controllers - just not doing the right thing any more.  What's worse is that temperature will affect the impedance, so some days/times it will work and others it won't.

 

So, in a nutshell - those splitters can help keep things going in an emergency, and there is nothing wrong with using them in a pinch.  However if weird things start happening, the very first thing to suspect is that the splitter is causing reflections.  If you can easily move the controller to the end-of-the-line you should do that instead  of using a splitter.  When things slow down, either ask us for a replacement jack (via Help Desk Ticket), or if you are not comfortable doing the work, send it in for repair.

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Sorry. Getting complaints. Some posted removed.

 

Thanks for keeping it civil. 

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And after you get them fixed and for those that read this before the season.  

 

1). Run a bead of hot glue along the top of the connectors and the board.

2). Zip tie your cat 5 cables to the controller somewhere. 

 

Speaking from experience.  This will save you a bunch of future headaches.

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Questionable terminology aside..... ;)

 

Using a 2-for-1 adapter like that can work in a pinch, however it is not recommended.  RS485 is great for sending a good amount of data out a long cable.  However one of the things it is very susceptible to are impedance mismatches and the signal reflections that happen because of them.

 

Signal reflections can wreak havoc across your entire display.  You won't damage anything, but you could be surprised to find 1 or 2 channels on a controller - or an entire network of controllers - just not doing the right thing any more.  What's worse is that temperature will affect the impedance, so some days/times it will work and others it won't.

 

So, in a nutshell - those splitters can help keep things going in an emergency, and there is nothing wrong with using them in a pinch.  However if weird things start happening, the very first thing to suspect is that the splitter is causing reflections.  If you can easily move the controller to the end-of-the-line you should do that instead  of using a splitter.  When things slow down, either ask us for a replacement jack (via Help Desk Ticket), or if you are not comfortable doing the work, send it in for repair.

 

RS485 architecture allows for "stubs" up to a certain length.  Here is a quick guide to help out for those that are wanting to run the calcs for whatever reason.  :P

(Page 3)

and even more http://www.nve.com/Downloads/ab6.pdf  

 

The second one uses a 10ns rise time instead of a 100ns.  Not sure what LOR uses since I didn't look it up.. ;)

 

It is always good to keep them as short as possible of course.. and as Mike said, if you do have signal issues the first thing I would check would be the splitter or "T" as many of the manufacturers call them.  This is a given.  I used what I think are hand wired "T's" that I got from Holiday Coro (if memory serves), and they were very reliable.   I used 6" stub cables and I had no issue with my string of about 20 something controllers with a LOT going on in the network given the slow speed setting I was using. 

 

The two I had to work around were in the middle of the pack electrically (so moving them to the end would have been a pain) and again, no issues data wise for me that I am aware of.  My total cable length for the over all system was about 400' of Cat5e.    But this option is a pretty good one in many cases for a work around to get you running again. 

 

If anyone runs into this issue and lives in the snow and ice region of the country, give it a try and let us know if it gives you any grief. I would be interested in how the temperature effects the outcome. 

Edited by plasmadrive

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Normally it's poor factory soldering and not the jack itself .... You can reflow the jack and then so as Jeff suggests to secure it going forward and also strain relief the cat5 wires somehow

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Normally it's poor factory soldering and not the jack itself .... You can reflow the jack and then so as Jeff suggests to secure it going forward and also strain relief the cat5 wires somehow

Both mine were bad jacks for some reason.. tried reflow but no joy.  Pins were aligned, no corrosion.. They had some other issues of which I didn't care to worry about at the time.  I just put the "T" in and a short cable and away they went.  I did replace the jacks later but didn't really worry about why they were bad once inspection showed no obvious defect under a magnifier..

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Normally it's poor factory soldering and not the jack itself .... You can reflow the jack and then so as Jeff suggests to secure it going forward and also strain relief the cat5 wires somehow

 

For strain relief I bought pre-made 1 ft network cables and "extender" connectors (that allow you to connect 2 shorter cables together to make a larger cable). I plugged the 1 ft cable into the jack on the board and the other end into the extender and these are kept both "inside" the enclosure. The i ran the cable to/from the next controller through the bottom of the enclosure into the extender. If you tug on that cable the extender will hit the bottom of the enclosure and is too big to go through. There is enough slack from the jack on the board to the extender that there's no strain put on the board.

 

For me, the advantage to this is that i can easily disconnect the network cable from the extender whereas if i zip-tied the network cable to the other power cables i'd be stuck with that cable unless i wanted to cut the zip tie.

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As an old (literally) telephone dude, I might point out that 95% of the time, the problem with either phone receptacles or cat 5 receptacles is that when unplugging the jack, one of the springy connectors pops over into another slot, thereby either shorting the receptacle or just removing a connection. Looking into the receptacle with a magnifying glass, you should see what looks like a comb, with a single gold wire between each tooth. Using a paper clip with the last 1/16 or so bent at 90 degrees, carefully untangle the gold colored connectors and lift and guide them into the correct slots. Be careful to not bend the wires/connectors. 

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I always zip tie my cat 5 cables to one of the channel cables. Push a little slack up and zip them. Has helped over the years... All my network cables are buried underground and found that the drain wire in the cat 5 was causing all my major issues. Trimmed it back and pulled it out the 45 connector and the best network I have seen in the last 7 years.

Edited by Jeff Messer

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I use a short patch cord to an RJ45-ECS connector  http://www.streakwave.com/Itemdesc.asp?ic=RJ45-ECS&eq=&Tp=%C2'> .  That keeps any stress off the board connectors as well as I don't have to open up a controller box to plug in the Cat cables.

My boxes have 2 of those ECS connectors on them, one on each side so I can daisy through easily.

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