Driller Posted April 11, 2009 Share Posted April 11, 2009 Hi, if anyone is still around here this weekend, in my Galaxy panel manual it says that up to a certain length I do not need to use twisted pair cable for the RS485 link to the keyprox. I think this was 100m. Most of my cameras are less than 20m to the DVR. I have only pulled two conduits per placement and I'm struggling to squeeze all the cable I need inside. Amateur error number 2 This is why I'm hoping to use thinner non-twisted pair for the 12v and the rs485. Could someone advise please? Thanks again chaps. Driller Link to comment Share on other sites More sharing options...
DirectFS Posted April 11, 2009 Share Posted April 11, 2009 Wouldn't like to use non shielded anything for RS485, unless a very short run. Not sure running 12V along a pair in the same seath as untwisted data is a good idea either....... Try it - be prepared to put a ferrite ring round the power pair, possibly both ends. To be fair, though Galaxys used to suffer with 485 bus problems (original ones anyway) it should be ok.......depending on distance from panel to keyprox. Bill. Hi, if anyone is still around here this weekend, in my Galaxy panel manual it says that up to a certain length I do not need to use twisted pair cable for the RS485 link to the keyprox. I think this was 100m. Most of my cameras are less than 20m to the DVR. I have only pulled two conduits per placement and I'm struggling to squeeze all the cable I need inside. Amateur error number 2 This is why I'm hoping to use thinner non-twisted pair for the 12v and the rs485. Could someone advise please? Thanks again chaps. Driller Bill Accord Fire & Security Services Ltd. www.accordfire.co.uk ~ TEL: 0845 474 5839 Link to comment Share on other sites More sharing options...
Driller Posted April 11, 2009 Author Share Posted April 11, 2009 Thanks Bill. I have 4 external cameras, 2 of which have a cable length of about 8 meters and 2 with about 17ish meters. I'll give it a try and as you suggested will try to get the 12V in another cable. It will be alongside though. Unfortunately I have to have the power cable for the flood associated with each camera running alongside the video cable for 3-4 meters, no choice. Link to comment Share on other sites More sharing options...
breff Posted April 11, 2009 Share Posted April 11, 2009 Use Cat5, one pair for rs485 and the other 3 pairs for power. The opinions I express are mine and are usually correct! (Except when I'm wrong)(which I'm not) Link to comment Share on other sites More sharing options...
Driller Posted April 11, 2009 Author Share Posted April 11, 2009 Use Cat5, one pair for rs485 and the other 3 pairs for power. Presumably you mean all in the same cable then. The three pairs for power, do you reckon I could drive 2 cameras off one cable (ie 3 pairs) or even 2 cameras and a PIR? Thanks for the advice. Link to comment Share on other sites More sharing options...
Driller Posted April 11, 2009 Author Share Posted April 11, 2009 Presumably you mean all in the same cable then. The three pairs for power, do you reckon I could drive 2 cameras off one cable (ie 3 pairs) or even 2 cameras and a PIR? Thanks for the advice. ETA Actually don't answer that, I'm going to read up on the resistances of the cable and the current draw of the cameras. Forums can make you lazy sometimes... Link to comment Share on other sites More sharing options...
Driller Posted April 12, 2009 Author Share Posted April 12, 2009 Try it - be prepared to put a ferrite ring round the power pair, possibly both ends. On closer inspection my cameras have ferrite rings around all cables, video, power and rs485. I guess you really do get what you pay for. Link to comment Share on other sites More sharing options...
SUBS Posted April 12, 2009 Share Posted April 12, 2009 WCertainly wouldnt do it myself, but I've seen a few camera installations where rs485 is run for hundreds of metres in 6 core intruder cable, just tapped off anywhere convenient, rather than daisy chained. I'd have said it wouldnt work, but it does, and has, problem free for years. Just goes to prove , you can 'get away with' quite a lot. Best thing is probaly to just try it. Link to comment Share on other sites More sharing options...
Guest RJBsec Posted April 12, 2009 Share Posted April 12, 2009 Best thing is probaly to just try it avoid it if possible. Whilst it might work, it isn't the best thing! Link to comment Share on other sites More sharing options...
SUBS Posted April 12, 2009 Share Posted April 12, 2009 Whilst it might work, it isn't the best thing! Dont get me wrong, theres no way I'd do it or condone a pro doing it. But this guy is doing it to his own house, and only asked if it would work. Link to comment Share on other sites More sharing options...
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