Guest Posted March 22, 2005 Share Posted March 22, 2005 And Georg - cable length is directly proportional to where you cut it! Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45223 Share on other sites More sharing options...
bellman Posted March 22, 2005 Share Posted March 22, 2005 And Georg - cable length is directly proportional to where you cut it! 45223[/snapback] Service Engineer and all round nice bloke ) The views above are mine and NOT those of my employer. Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45245 Share on other sites More sharing options...
Guest Posted March 22, 2005 Share Posted March 22, 2005 45245[/snapback] hmm.. i think i missed to think something...??????? That would mean that I just learned something.. (never had to think relationship between NVP and capasitance) IF I learned something it would mean that different conduits (ie copper vs aluminium) will have different capasitance. Nothing thou rings the bell in my head that formula of capasitance would consist of the conductivity of the conduit.. Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45263 Share on other sites More sharing options...
Guest Posted March 22, 2005 Share Posted March 22, 2005 and sorry for my engrish Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45264 Share on other sites More sharing options...
Service Engineer Posted March 22, 2005 Share Posted March 22, 2005 But capasitance depends also of cable lenght and is usually announced as pF / 1km .Their are MANY other factors that determine CAPACITANCE Georg.. But I`d really like to know why you want to how to measure it..? ........................................................ Dave Partridge (Romec Service Engineer) Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45266 Share on other sites More sharing options...
Guest Posted March 22, 2005 Share Posted March 22, 2005 Their are MANY other factors that determine CAPACITANCE Georg.. But I`d really like to know why you want to how to measure it..? 45266[/snapback] Thanks Dave, I really felt lost while spelling CapaCitanCe in my mind.. How to measure? With a capacitance meter of course.. Why so important? Because it causes a squarewave signal to look like a sinewave signal and that isn't good for data transmission.. Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45271 Share on other sites More sharing options...
Service Engineer Posted March 22, 2005 Share Posted March 22, 2005 Hmmm Short runs use RS232, long runs use RS422. I`d like to know at what point you would consider the capacitance too high..? ........................................................ Dave Partridge (Romec Service Engineer) Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45277 Share on other sites More sharing options...
Guest Posted March 22, 2005 Share Posted March 22, 2005 Hmmm Short runs use RS232, long runs use RS422. I`d like to know at what point you would consider the capacitance too high..? 45277[/snapback] or RS485 (thou i don't have a slightest idea of difference between 422 and 485).. I would also be interested of the knowledge when capacitance is too high.. But obviously it is too high if data isn't going through.. I think it is calculatable of speed of data and maximum desired cable length (therefore NVP..???? ) Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45278 Share on other sites More sharing options...
Guest Posted March 22, 2005 Share Posted March 22, 2005 and REALLY long runs use TCP/IP.. Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45279 Share on other sites More sharing options...
Service Engineer Posted March 22, 2005 Share Posted March 22, 2005 LOL Georg, you`ll be rambling on about FM and FSK next... ........................................................ Dave Partridge (Romec Service Engineer) Link to comment https://www.thesecurityinstaller.co.uk/community/topic/5462-alarm-installation-cable-type-query/page/6/#findComment-45280 Share on other sites More sharing options...
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