Troy_Connor Posted November 1, 2012 Share Posted November 1, 2012 I thought this may be helpful for some of you. I have some long runs, and I plan on using this to save on cable. Hope it helps. Link to comment Share on other sites More sharing options...
Max-Paul Posted November 1, 2012 Share Posted November 1, 2012 (edited) Whoeth on yea who do not follow the rules of the white papers. All I got to say is this. If you can get away with it, fine. But if you start getting strange blinking of the lights and some times cant find controller A and other times you can see controller A but now B is not there. Then quit screwing around and follow the rules.For me and mine, we will follow the rules. I really dont want to be out in the middle of winter rerouting Cat5 cables and scratching my head and arse trying to figure out what is wrong.Let me repeat the rules here for all of you wondering what I am referring to. RS-485 was designed to be wired daisy chain. A terminating resistor at both ends of the cable. So, one should be in the adapter and if you really want to do it right. One should be in the second jack of the last controller on the daisy chain. Disclaimer, not always needed. But I have seen a few others add it when having problems and it cleared things up. But in industrial installations, you will find them always. Scrapping thousands of dollars worth of products is not the same as a Christmas light show that has hick-ups. Edited November 1, 2012 by Max-Paul Link to comment Share on other sites More sharing options...
edvas69 Posted November 2, 2012 Share Posted November 2, 2012 I agreee here with Max-Paul, once you start venturing away from the standard you then start to expose yourself to unexpected results. It may work for you but it may not work for all as each installation is different and ussually when issues arise its more times than not a combination of issues that when together can create frustration.The reason why they are daisy chained is because if you use a splitter then you can start to generate reflecting signals with in the data line which can cause many issues. The cheap holiday coro controllers use this method but as has already been seen that having multiples (eg 20 or more) of these on the same network can create this issue. normally a 120 ohm signal terminator will reduce/stop the reflected signal, but not in every case and in situations like this you would need to divide the network up.So im a strong believer in standards as standards help us make the correct decisions that will minimise issues. Link to comment Share on other sites More sharing options...
Tim Fischer Posted November 2, 2012 Share Posted November 2, 2012 I thought this may be helpful for some of you. I have some long runs, and I plan on using this to save on cable. Hope it helps.I've been known to be dense, but I'm not quite sure what this is demonstrating. Link to comment Share on other sites More sharing options...
Orville Posted November 2, 2012 Share Posted November 2, 2012 (edited) I've been known to be dense, but I'm not quite sure what this is demonstrating.Me too Tim. I looked at those pics and they make no sense to me either.Only thing I could get out of them was the info in them that say they are "ethernet", and that is a definitive NO NO with LOR Controllers unless you want to damage or ruin your controllers and possibly anything attached to them. It may work for a while but it is NOT recommended to use anything ethernet specific {like splitters, routers, non LOR USB485 dongles, etc}. with the LOR system.@"those thinking the cat5 jacks are split in the controllers": Now if someone is thinking those cat5 jacks in the controllers are split, you would be and are incorrect, they are both wired in PARALLEL with each other, not series, not split like you may be thinking, and is why you can use either one for running the cat5 to the next or last controller and it also does not matter which cat5 jack you use on the last controller, either works just fine. Although most will use the center jack. Edited November 2, 2012 by Orville Link to comment Share on other sites More sharing options...
Max-Paul Posted November 4, 2012 Share Posted November 4, 2012 Problem we have here Drew is that we have many people who have no idea about white papers. Or about reflected signals. These are doctors, bankers and lawyers that are putting together a display. To have someone come in here and start talking about some strange single cable that has data go and come back on the same cable. Well people go, gee thats a great idea. Then when things dont work, they wonder why. If you have advanced knowledge about what the RS-485 network is about and can trouble shoot. Then go on and try some advanced stuff. But please do not advance this idea to the masses who barely understand the concept of daisy chaining is all about. And frankly, I rather have a solid network than saving a few feet of Cat5 cable. Maybe people viewing my display might not understand why the lights over here are or arent blinking. But I will know and it will drive me crazy. Link to comment Share on other sites More sharing options...
George Simmons Posted November 4, 2012 Share Posted November 4, 2012 I guess I don't understand either. Cat 5 cable couldn't be much more inexpensive than it already is. The entire LOR system, whether you're using 2 controllers or 52 is as rock solid as it can be if you set it up as they designed it. Sometimes I over-simplify, but I don't understand trying to make an already round wheel roll smoother than it already does. Link to comment Share on other sites More sharing options...
Guest wbottomley Posted November 4, 2012 Share Posted November 4, 2012 I guess I don't understand either. Cat 5 cable couldn't be much more inexpensive than it already is. The entire LOR system, whether you're using 2 controllers or 52 is as rock solid as it can be if you set it up as they designed it. Sometimes I over-simplify, but I don't understand trying to make an already round wheel roll smoother than it already does.You couldn't have summed it up better. 55 here and rock strong. Link to comment Share on other sites More sharing options...
plasmadrive Posted November 4, 2012 Share Posted November 4, 2012 (edited) Well I can hardly read that picture, but if he is thinking about using a single Cat cable pair to go and another to return to feed another unit.... there should be no issue with that. First off the Cat pairs are rated far above the speed we are using them for (assuming RS485). Secondly the RS485 architecture is a very robust and noise immune system when done right. Consider that RDM protocal will feedback on the second pair of the 5 pin XLR cable with no issue. Using RJ45 connectors the standard for two data pairs is as follows. RJ-45 pinoutData 1+Data 1-Data 2+Not AssignedNot AssignedData 2-Signal Common (0 V) for Data 1Signal Common (0 V) for Data 2So, if that is what he meant.. why not? If that is not what he mean.. Never mind.. PS.. here is a good link for those that care. http://www.lammertbies.nl/comm/info/RS-485.html Edited November 4, 2012 by plasmadrive Link to comment Share on other sites More sharing options...
R Weiland Posted November 4, 2012 Share Posted November 4, 2012 Well I can hardly read that picture, but if he is thinking about using a single Cat cable pair to go and another to return to feed another unit.... there should be no issue with that. First off the Cat pairs are rated far above the speed we are using them for (assuming RS485). Secondly the RS485 architecture is a very robust and noise immune system when done right......Plasmadrive; I think you captured and refined the point that Troy was trying to make. However, Max-Paul brings up a valid point regarding the vast number of non technical LOR users who will be even more confused!And to All: Just because you can, doesn't mean you should. Link to comment Share on other sites More sharing options...
plasmadrive Posted November 4, 2012 Share Posted November 4, 2012 ......And to All: Just because you can, doesn't mean you should.Now THAT is an understatement! Link to comment Share on other sites More sharing options...
Max-Paul Posted November 5, 2012 Share Posted November 5, 2012 Just a bit more to chew on. In the white papers, you are only allowed 32 devices per segment before putting in a repeater. Cause the original RS-485 transmitter, receiver chip limitations. Now I have been informed that LOR for one uses a new advanced chip that I dont believe has a limitation on the number of devices up to what was it 240 devices. So one of my concerns is also what are the chances of cross talk using two pairs of cable pairs as outlined above? Link to comment Share on other sites More sharing options...
dmoore Posted November 5, 2012 Share Posted November 5, 2012 There is theory and there is practice. I've put just under 100 DMX controllers (which run twice the speed on 485 that the LOR protocol runs at) and had it work. Maybe some educational material would be useful here:How the LOR and DMX Protocols works - pro's con's and details:http://www.holidaycoro.com/kb_results.asp?ID=21If you are looking for "the" article by people who make a lot of RS485 chips - here it is:http://www.maximintegrated.com/app-notes/index.mvp/id/763For some hands-on with the effect termination has on a RS485 connection:http://www.holidaycoro.com/kb_results.asp?ID=17 Link to comment Share on other sites More sharing options...
ehgilman Posted November 11, 2012 Share Posted November 11, 2012 Could some one answer this in English???? I am a litle techy, but holly crap you have me lost.... Instead of a spiltter, couldn't one use a Switch or router? (Not conected to any other devices but LOR equipment???? Link to comment Share on other sites More sharing options...
Tim Fischer Posted November 11, 2012 Share Posted November 11, 2012 Instead of a spiltter, couldn't one use a Switch or router? (Not conected to any other devices but LOR equipment????No. LOR (and DMX, with the exception of E1.31) is NOT Ethernet and you cannot use Ethernet switches or routers. If you try, you're likely to damage something. Link to comment Share on other sites More sharing options...
-klb- Posted November 11, 2012 Share Posted November 11, 2012 Also of interest, at a quick look, what is documented above is typical DMX on RJ-45 pinouts, not LOR pinout. Odds are most users will cost themselves more in time trying to do non standard wiring than they will save on materials. Link to comment Share on other sites More sharing options...
ehgilman Posted November 11, 2012 Share Posted November 11, 2012 Kewl, Glad you told me that so when I expand, I wont cook anything.... Link to comment Share on other sites More sharing options...
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