Deltaseven Posted October 2, 2004 Posted October 2, 2004 When using EOL, what is the purpose behind linking out unused zones at the panel? The zones are obviously isolated in the panel programming. One of our engineers was expounding his theory that open unused zones (no resistors) can cause feedback to used (and correctly wired) zones. We mainly use Castle Care-tech kit, and they have no requirement to link out unused zones and I have not noticed a problem. I must confess that I can't see how this interference would come about. The way I see it, each zone is completely isolated from all the others, and only share a common ground. Any thoughts? D7
CompostCORNER Posted October 2, 2004 Posted October 2, 2004 The only benefit I can see for linking out unused zones on an EOL panel would be that the resistors are there ready and waiting if the system is ever expanded.
Service Engineer Posted October 2, 2004 Posted October 2, 2004 There`s no purpose to linking out unused zones on an EOL system. Its just an old habbit many engineers have from the old NC loop days. ........................................................ Dave Partridge (Romec Service Engineer)
Guest Posted October 2, 2004 Posted October 2, 2004 And your always gonna have the correct resistors on site if you need them.Pete 25698[/snapback] Gee, man.. I have a huge box of different kind of resistors in the car.. Enough to make any size resistor if something is missing.. This of course only if our "resistor supplier" has already closed and I have to make alarms working for the night..
black knight Posted October 2, 2004 Posted October 2, 2004 galaxy advise you put EOL resistors in any unused zones on board / on RIOS , it helps to keep system balanced and helps tp prevent f/a i think ! THE BLACK KNIGHT "Any comments / opinions posted are my opinion only and do not represent those of my employer or Company."
Guest Posted October 2, 2004 Posted October 2, 2004 galaxy advise you put EOL resistors in any unused zones on board / on RIOS , it helps to keep system balanced and helps tp prevent f/a i think ! 25709[/snapback] I think that also DSC advises that you put EOL in unused zones. Though my guess is that it is very marginal amount of FA/trouble this prevents.
breff Posted October 3, 2004 Posted October 3, 2004 Black Knight is right about the galaxys. I was told to close unused zones as open collectors can pick up interference. The opinions I express are mine and are usually correct! (Except when I'm wrong)(which I'm not)
Guest Posted October 3, 2004 Posted October 3, 2004 Black Knight is right about the galaxys. I was told to close unused zones as open collectors can pick up interference. 25823[/snapback] Just a lucky guess, but I don't think that zone inputs are open collectors... PGM:s are usually, but not the zones.. Open collectors are used to pull to ground when activated (small voltage to the Base). And common is same as ground. (dont mix this with earthing, nothing to do with that though it can be earthed in some PCB:s) So there is nothing to measure then between the com and com (0 and 0)..
Guest ALSEC Posted October 4, 2004 Posted October 4, 2004 It can't hurt to put them in can it - good pratice?
Guest Posted October 4, 2004 Posted October 4, 2004 It can't hurt to put them in can it - good pratice? 25942[/snapback] good habbit?
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