k6ccc Posted July 21, 2015 Share Posted July 21, 2015 Note that the termination that jstorms listed has the resistor between pins 1 & 2. This is the standard pins for DMX equipment, NOT for LOR controllers. Link to comment Share on other sites More sharing options...
jstorms Posted July 21, 2015 Share Posted July 21, 2015 Looking at the iDMX docs it says put the resister between pins 2 & 3, is this correct?http://www.lightorama.com/Documents/iDMX-1000_Man_Web.pdfThe maximum length of all cable in a DMX512 network is between 1,000 and 1,500 feet, depending upon the number of DMX fixtures daisy chained. The maximum number of ‘loads’ (usually fixtures) in a daisy chain is 32. It is important to use good quality cables and make sure the network is terminated. ‘Terminated’ means placing a 120 Ω ¼ w resistor between pins 2 & 3 of the cable of the last DMX512 device in the network. Link to comment Share on other sites More sharing options...
k6ccc Posted July 21, 2015 Share Posted July 21, 2015 That's when using an XLR connector for DMX not an RJ-45. Link to comment Share on other sites More sharing options...
godman Posted July 21, 2015 Author Share Posted July 21, 2015 Just when I thought I knew it all!! It amazes me that in this hobby it seems like there is always something new to learn? In the 18 months since I started this Hobby, I have NEVER heard of the word terminator or had noticed it being discussed? Hmm... I would be curious to see who even uses a terminator, do the LOR controllers in LOR mode use or require a terminator? Link to comment Share on other sites More sharing options...
zman Posted July 21, 2015 Share Posted July 21, 2015 (edited) DMX termination is DMX termination. Does not matter WHAT cabling is involved. It is between pins 2&3 period. You can debate this till the chickens come to roost. The DMX512A as defined by ESTA, states that a terminator needs to be at the end of a chain. Drop a pebble in a pond near a rock, the waves hit the rock and bounce. David's video that John posted is the proof. A lot of folks do not use terminators and say they have no problems. However, if they start to have weird things happen, generally speaking this is the source of the problem. I am not certain, but I believe termination is built into the pixels, but would have to validate that somehow. I have been using DMX in my display, for 9 years now. I have always terminated, and never had issues AGAIN, that is in my traditional DMX universe which runs, Yokes, Floods, Theatrical Zap Strobes. For me, that is run from an iDMX1000. It is LORs Enttec Pro. Some getting into RGB have just jumped into E1.31 and not fully understood the DMX foundation and therefore would not have run into any termination discussion. E1.31 is DMX run via Ethernet. So instead of one serial universe, you get multiple universes in either Multi-cast or Uni-cast fashion. If I jumped off an E682 to a DMX universe, if it had LOR controllers, or a flood light at the end, I would put a terminator on it. Edited July 21, 2015 by zman Link to comment Share on other sites More sharing options...
k6ccc Posted July 21, 2015 Share Posted July 21, 2015 For my three LOR networks, I have terminations on two of them. My regular network goes all over the place with controllers scattered along the length. The Aux A network is only about 50 feet of cable with one controller on it and I don't have a termination on it. My Aux B network (only used for Christmas) is currently the only one running at 500K speed and has three CCP controllers on it. I have a terminator on the end. For 2015, Aux A and the Regular network are going to get shuffled around some because some of my older controllers can't use the new Enhanced Protocol and they will end up on the Aux A network, and the controllers that can handle the new enhanced protocol will all be on the Regular network. In the process of that shuffle, all three networks will be properly terminated. As I said a few posts above, you may well get away without terminators, or maybe have minor issues and never notice them. There are several factors that will increase the likelyhood of needing terminators:Complex network (mainly that means lots of nodes),Long total length of cable (what works with 300 feet of cable may not work with 3,000 feet of cable),Higher data rate (what works at 57.6K may not work at 500K). Here is a forum post on terminators. See post #7http://forums.lightorama.com/index.php?/topic/8769-some-channels-come-on-and-stay-on/?hl=terminator#entry72906 Link to comment Share on other sites More sharing options...
k6ccc Posted July 21, 2015 Share Posted July 21, 2015 DMX termination is DMX termination. Does not matter WHAT cabling is involved. It is between pins 2&3 period. Mark,I'm going to disagree with you here. Pins 2 & 3 is correct for XLR connectors (and yes, I know that officially XLR is the only way to carry DMX). However for themany pieces of DMX equipment that uses RJ-45 connectors, the RS-485 data is on pins 1 & 2 so the terminator needs to go onto pins 1 & 2 of an RJ-45. For LOR equipment, the RS-485 data is on pins 4 & 5 (regardless whether it's LOR or DMX protocol), so the termination needs to go on pins 4 & 5. BTW, I completely agree that we SHOULD all be running termination on our RS-485 systems - LOR or DMX. This is particularly true for higher speed networks... Link to comment Share on other sites More sharing options...
zman Posted July 21, 2015 Share Posted July 21, 2015 Jim, Right. Rule number one, never multi-task on a conference call at work and answer LOR questions at the same time. I never had to worry about RJ45 connections so it was not on my brain, but yes on RJ45's yes it is 1 & 2. Sorry about that and the confusion. Link to comment Share on other sites More sharing options...
godman Posted July 21, 2015 Author Share Posted July 21, 2015 (edited) So then the connectors that John referred to will work?http://www.stageligh...X512-Terminator Edited July 21, 2015 by godman Link to comment Share on other sites More sharing options...
k6ccc Posted July 21, 2015 Share Posted July 21, 2015 So then the connectors that John referred to will work?http://www.stageligh...X512-Terminator Only if you are using DMX equipment with RJ-45 connectors. If you are using LOR controllers, the termination needs to be on port 4 & 5. Link to comment Share on other sites More sharing options...
k6ccc Posted July 21, 2015 Share Posted July 21, 2015 Jim, Right. Rule number one, never multi-task on a conference call at work and answer LOR questions at the same time. I never had to worry about RJ45 connections so it was not on my brain, but yes on RJ45's yes it is 1 & 2. Sorry about that and the confusion. Sure you can Mark - just ignore the work conference call. Just because they are paying you what makes them think that you should actually be doing work for them? Seriously, thank you for confirming that I was right on that. You are pretty much the foremost authority on DMX around here and calling you out was sort of like taking a flying leap! Except for the test I referred to in post #3, I have never done anything with DMX over RS-485. Lots of E1.31 however...Apparently I was paying attention to posts that I read... Link to comment Share on other sites More sharing options...
zman Posted July 22, 2015 Share Posted July 22, 2015 We all have brain farts, and I have more than my fair share Link to comment Share on other sites More sharing options...
Greg Young Posted July 23, 2015 Share Posted July 23, 2015 Like Mark and Jim, I have always terminated my 485s (LOR) with terminating resistors. I use 1/4 watt (or was it 1/8.. it's been a while), that I install inside a 1.5 inch long length of CT5e cable that the other pairs if wires were removed from. That is then crimped in place to the plug, so it can be plugged into any controller that winds up being on the end of the line. I made up a half dozen (as I terminate the end controllers that are on feeds from my various ELLs.)I do similar for DMX, using different pin outs as described above. Link to comment Share on other sites More sharing options...
jstorms Posted July 27, 2015 Share Posted July 27, 2015 So I could build a universal terminator where pins 1&2 are terminated and pins 4&5 are terminated, or would this cause unintended problems (fires)? Link to comment Share on other sites More sharing options...
k6ccc Posted July 27, 2015 Share Posted July 27, 2015 Off hand, I would think so. In fact if I remember right on LOR controllers pins 1&2 pass through from input to output without any connections on the board. There was discussions in the past with shorting those pins at the far end and then detecting the short at the near end as a theft detection. Detecting a termination is better because it's easier to detect a circuit fault - that's the way fire alarm loops normally work. Link to comment Share on other sites More sharing options...
Taito80 Posted August 4, 2015 Share Posted August 4, 2015 I have a similar issue that I can simply not figure out. I have an CTB16 controller. I am sending it DMX from a pixlite board but for some reason, the lights do not light up. I have configured it as universe 1000 with 16 channels and i have it set to be constantly on for channel 1. From what I can tell, the LOR is receiving the DMX signal because the light on channel 1 will briefly come on and go off during the effect but that is it. I am stumped at this point, any help would be appreciated. Thanks. Link to comment Share on other sites More sharing options...
Dennis Laff Posted August 4, 2015 Share Posted August 4, 2015 Light o rama network only shows up to 999 universes try going under 999 see what happens. Link to comment Share on other sites More sharing options...
Taito80 Posted August 5, 2015 Share Posted August 5, 2015 just tried it, reduced it to 500 and still nothing. i am wondering if it is a firmware issue on the controllers? both of my controllers are original firmware from when i bought them (2012/2013) and i cant find the damn usb to serial connector so i have no way of knowing what the firmware on them is unless someone can tell me another way to get it. Link to comment Share on other sites More sharing options...
Dennis Laff Posted August 5, 2015 Share Posted August 5, 2015 Do you have the DMX address set right for the lor box using the light o Rama dmx conversion chart. Link to comment Share on other sites More sharing options...
Dennis Laff Posted August 5, 2015 Share Posted August 5, 2015 One more thing if your running the lor box out of the pixelite board you need a crossover cable. (Holiday Coro sells them). Link to comment Share on other sites More sharing options...
Recommended Posts