jim6918 Posted February 5, 2010 Share Posted February 5, 2010 I want to add a controller for next year on the opposite side of my house from where my master controller box is situated. It isn't over 100' depending on how I route it. I was considering a set of ELL, but now wondering why spend all that money when I can run 100 feet of CAT 5E and accomplish the same thing. I currently run 300' to 500' with CAT5E at work on 10/100 networks just thru cheap powered switches with no data loss. I buy the CAT 5 in bulk and crimp my own RJ45's.What experience do the pros here have considering cable length and LOR? Link to comment Share on other sites More sharing options...
mmais68569 Posted February 5, 2010 Share Posted February 5, 2010 I had the same thought you had a few weeks ago, whether to buy the EL or run Cat 5. I decided to run cat 5 & save my $249.00. I was trying to cut down on the number of extension cords I had to run. With using the cat5 all I need to run is 2 cords to supply power & not 16 cords from the house. Save your money & use Cat.5 Mike Link to comment Share on other sites More sharing options...
Bill Hoffman Posted February 5, 2010 Share Posted February 5, 2010 Hi Jim, As far as using the cat5, as long as it is less than 100', you shouldn't have any problems. I have the light linkers, but I have only used them one year when I controlled my neighbors lights across the street. I use the direct cat5 link to the computer only now, with no problems at all. Actually, when I used the light linkers the one year, I had to move the linker that was across the street around because I think a big oak tree in his front yard was blocking the signal. Once I got it out from behind the tree, it worked fine. But since I don't use his house anymore, he moved, I use the direct link. I would save the money, buy a couple of more controllers, and use the cat5, if it's less than 100', and you don't mind running the single wire.Bill Link to comment Share on other sites More sharing options...
-klb- Posted February 5, 2010 Share Posted February 5, 2010 The 100 foot limit is only if you are powering a SC-485 adapter over the cable. Other limits may apply if other devices are being powered over the cat 5 from the controllers. But between a USB adapter and a controller, or between controllers, you can have any fraction of the 2,000 foot max buss length you want.At home, my first run from the computer starts upstairs, near the front, runs down the hall to the back room over the rear entry garage, down through a little attic space between the two, then into the garage, out through the door, and around the side to the controllers. Probably around a couple hundred feet...At the fire house, several of the the runs are over 100 feet. For example, from the computer at the front, around to the back. Or under the alley, and up to the first controller location. Heck, with the way some of the conduits run, two controllers that are 20 feet apart may have 150 feet of cable in between them. I think that one network has about 600 feet of cable in conduits, plus whatever other short (typically 6 to 10 foot) cables are connecting the 20+ controllers together in the clusters they are in...So, don't worry at all about a 100 foot cable, as long as you are not powering any of the LOR devices over it... Link to comment Share on other sites More sharing options...
Max-Paul Posted February 5, 2010 Share Posted February 5, 2010 klb,I respect your knowledge, but I do have to ask you a question about a statement you made in your last post. I am of mind from my own readings that RS-485 has a theoric max range on a single segment of 4000'. but if you had a repeater it is another 4000'. And I say again this is a perfect network. I just want to understand why you mention 2000'? is this from pratical experience? Link to comment Share on other sites More sharing options...
LightORamaDan Posted February 5, 2010 Share Posted February 5, 2010 Max-Paul wrote: klb,I respect your knowledge, but I do have to ask you a question about a statement you made in your last post. I am of mind from my own readings that RS-485 has a theoric max range on a single segment of 4000'. but if you had a repeater it is another 4000'. And I say again this is a perfect network. I just want to understand why you mention 2000'? is this from pratical experience?The 4000' limit depends on a number of parameters including te baud rate, number of connections, etc... 2000' is a more realistic real-world number. We have seen it work at the full 4000' but when asked I generally say 1/2 mile. As you suggested, a repeater will increase the range.As far as the original question. I would use a wire rather than spend the money on the ELLs. Can get another CTB16PC-ReadyToGO with the $249!Dan Link to comment Share on other sites More sharing options...
-klb- Posted February 5, 2010 Share Posted February 5, 2010 Dan, you beat me to the reply. I was going to say that I thought I had read the 2,000 foot number in the LOR product literature, and that a number of factors come into play to explain the discrepancy. Possibly the biggest one is not using terminators on the ends of the line. Others come from cumulative signal losses from all the RJ-45 connectors. Some of it is just giving yourself a x2 engineering margin.As for the repeaters, they probably need to be within 100, or 50 feet of a controller for power, and at some crazy distance, (and number of repeaters) the time from one end to the other, including delay in the repeater will be enough that it may interfere with polling for interactive events..... Unlike ethernet, where the max time (cable length) from one end of a segment to the other is actually part of the specification, RS-485 leaves it undefined. With RS-485, it is left to the application to define the max acceptable time from one end of the network to the other. Though a smart repeater that was application aware may even be able to step around that to some extent, by caching a response in one polling cycle to propagate back to the computer in the next polling cycle....By the way, the cat 5 for the firehouse and park pretty much take up about a 16 gallon tote all by itself... I'm sure some of it is not in use, but not much. I know one year we replaced a couple of 100 foot cables that had been hooked together with a single custom fit run, and I've been cutting up the 100 footers to make shorter ones to run from controller to controller.. This year I replaced at least one cable end that was rather corroded. I'm pretty sure it was one of the ones that was plugged into that RJ-45 coupler the first year in a place we really could not adequately protect.. Link to comment Share on other sites More sharing options...
DaveK Posted February 5, 2010 Share Posted February 5, 2010 I used an ELL for the first time this year. I had two controllers on top of my roof – and I have a two story home. Because of placement of other controllers Cat3 wasn’t an option. The ELL ran flawlessly all season long. Also use a set of ELLs on a commercial job I did in Ohio. Same result; flawless. Cat5 is cheaper and should be used as a first option but there are instances that an ELL is invaluable. Link to comment Share on other sites More sharing options...
jim6918 Posted February 6, 2010 Author Share Posted February 6, 2010 As far as the original question. I would use a wire rather than spend the money on the ELLs. Can get another CTB16PC-ReadyToGO with the $249!DanOh Dan, You have such a nack of cutting through the fog with some of these questions. I just wanted to verify the distances possible. Thanks again evrybody. Link to comment Share on other sites More sharing options...
Max-Paul Posted February 6, 2010 Share Posted February 6, 2010 klb, I would imagine part of the reply timing factor might be effected by baud rate? And I agree with the 2x engineering factor. I know that this will sound strange, but I am of mind to build things like the old school germans were known for. I was tutored under my grandfather who came from the fatherland when he was 21.The bit about 4000' is just me quoting white paper stuff. Thanks for your reply along with Dan's.. Link to comment Share on other sites More sharing options...
-klb- Posted February 6, 2010 Share Posted February 6, 2010 In ethernet, it is a pure speed of light in copper issue, and that they only want to listen so long for collisions in a collision domain. (back when hubs and half duplex were far more common than switches and full duplex) Also, to limit the odds of a collision.In theory, on a serial link, how long it takes from when you finish sending your query, to when you start receiving the reply is actually independent of the baud rate. The length of time to transmit the query will vary with baud rate, but the delay between the end of transmitting, and end of receiving the query will not vary with baud rate. Delay before starting to answer should depend entirely on the hardware at the end, not the communication speed, and the start of the replay should take the same length of time to make it back through the wire no matter what speed it is running as well. Even though the message takes longer at lower rates, ideally the master node realizes that a message is coming in fairly quickly at the start of reception, and will just wait for it to finish before taking back over the buss. Link to comment Share on other sites More sharing options...
Max-Paul Posted February 6, 2010 Share Posted February 6, 2010 Very well explained klb. I was not thinking along those lines but I see your point. Thanks Link to comment Share on other sites More sharing options...
Guest guest Posted February 7, 2010 Share Posted February 7, 2010 LightORamaDan wrote: As far as the original question. I would use a wire rather than spend the money on the ELLs. Can get another CTB16PC-ReadyToGO with the $249!DanExactly what I did! I was wrestling with that same question myself over on the PC forums and got the same advice. So instead of just 2 CTB16PC complete controllers and a set of ELL's, I bought a 3rd CTB16PC. If you really have no need for the ELL, I wouldn't use them, but go with the cat5 cable too.Got me another controller and 64 channels, instead of 48 I had planned by taking the "cat5" route. Link to comment Share on other sites More sharing options...
Redbirdruss Posted February 8, 2010 Share Posted February 8, 2010 But being wireless is COOL! Link to comment Share on other sites More sharing options...
Redbirdruss Posted February 9, 2010 Share Posted February 9, 2010 Jeff Millard wrote: Redbirdruss wrote: But being wireless is COOL!This has my vote for quote of the week! JeffHehehe... I'm hooked Link to comment Share on other sites More sharing options...
Redbirdruss Posted February 10, 2010 Share Posted February 10, 2010 St. Louis Cardinals Link to comment Share on other sites More sharing options...
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