Vsita 15P programming question

All electrical and electronic manufacturers designate "normally open" as the device state when the relay, switch, etc is in its resting state with no signal applied. Therefore, if no magnet is applied to a reed switch, the contacts are not closed and the switch is "normally open". However, my Ademco manual talks about normally open circuits vs. normally closed circuits. Is "normal" in alarm language considered to be with all windows and doors closed with no alarm condition? Or is the normal state considered to be when the windows are open, no magnet applied, contact open? The book does not make a distinction between the definitions as related to devices vs. circuits and their explanation is somewhat ambiguous. I suppose I could program it both ways and see which one works, but it would be easier to do it right the first time.

Bob

Reply to
Robertm
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Good grief, how old ARE you? I worked in the electronic industry for 40 years and never came across what you describe.

Bob

Reply to
Robertm

To carry this one step further, then it would mean the EOLR would be in series instead of being in parallel with the last device on the line? If that's the case, then it would make no difference if the EOLR is at the last device or in the can.

Bob

Reply to
Robertm

I wasn't a tech, I'm an engineer, designed and built industrial test equipment.

Bob

Reply to
Robertm

Yes, you are correct. I was thinking the fault would be an open. With only one device on the line, it's highly unlikely that the wire would somehow short together in the cable but I suppose anything is possible. Someone might drive a nail into the wall or a rat might chew into the wire.

Bob

Reply to
Robertm

Well, sort of. Years ago it varied somewhat from one manufacturer to the next.

Yep.

Yes, panel circuits (aka "zones") are described as "normal" when the sensors are in a non-violated state. In the case of a door contact that means when the magnet is lined up with the sensor (i.e., the door is closed). In the case of a motion detector it means the detector has power running to it and the sensor is not presently sensing motion -- that is, the circuit is closed.

Reply to
Robert L Bass

I can't explain why you didn't notice. Perhaps like most techs you only used one brand. I've tried almost all the major makes over the years and I've installed and serviced thousands of systems. I can't claim to have seen it all but I've acquired a fairly broad range of knowledge of the trade.

Reply to
Robert L Bass

Yes, that is correct.

No, that is not correct. If the zone is shorted out between the can and the last device and the resistor is at the last device the zone would show either a "trouble" or "alarm" state, depending on the arming status of the system. If the same thing were to happen with the EOLR in the can the zone would show "normal".

Reply to
Robert L Bass

Yes, my only previous alarm experience was my old Ademco relay panel several years ago. Every industry has its own quirks, its own terminology.

Bob

Reply to
Robertm

Most residential type thieves aren't going to try to bypass an EOLR. If anyone breaks in, it'll be the kid on meth who will use a more direct approach. Kick the door in, grab what he can and run. If I'm home, he may very well die from lead poisoning. If I'm not home, he'll be scared off by the noise. If he is stupid enough to stay, the police will arrive an hour later and tell him that what he did wasn't nice.

Bob

Reply to
Robertm

You haven't figured out that RLB has a comment for everything?........and most of it is based on many years ago when he claims to have installed. He is careful to make it sound like it was just yesterday, probably trying to maintain some sort of credibility with his DYI market, but then again he knows people are watching him. Sometimes he slips up and is caught and people call him on it.

Reply to
Bob Worthy

I think if someone is breaking down door at night, their intent wouldn't be to wish me a pleasant evening. By law I would have to wait until they crossed the threshold and then view them as a threatening person who intended me bodily harm. It's unlikely to be some beautiful blonde looking for a sexy senior citizen.

Bob

Reply to
Robertm

That explains it. Your experience is in a different industry.

Reply to
Robert L Bass

An open circuit would only indicate that the door was open (or that the wire had been cut).

True, but EOL supervision is intended to protect against deliberate tampering as well as accidental damage. FWIW, most alarm techs either don't bother with EOL resistors at all or mistakenly place them in the panel where they are useless. The incidence of deliberate tampering is low enough that thgis rarely presents a problem. However, it can and does happen on occasion, mostly in commercial apps where a dishonest employee may try to disable the protection.

Or a rat may have installed the wire in the first place. :^)

Reply to
Robert L Bass

Reply to
Robert L Bass

That's a while ago. ISTR the oldest Ademco I serviced was a 342R or some such. I've also pulled out a lot of ancient systems and replaced them with more modern stuff over the years. You'd get a kick out of the motorized devices that were used to transmit codes over leased lines way back when.

Reply to
Robert L Bass

True indeed. The reason for using EOLR's in a residential location is mainly to detect accidental shorts. These, too, are rare but they can happen. As I said before, most techs don't even bother with them although in public most insist that they *always* do it right. :^)

Just be careful not to hurt the wrong person.

Reply to
Robert L Bass

Tell me what you're going to detect with an EOLR at the correct position in a loop with 15 windows/door switches and one of those windows (somewhere is opened)...what are you supervising?...the return leg thats all.

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Reply to
Crash Gordon

"Robert L Bass" a écrit dans le message de news: ovudnYOTocX0eafenZ2dnUVZ snipped-for-privacy@comcast.com...

are you talking about electronic manufacturer or alarm manufacturer...

cause it was never the case with electronic manufacturer....

and alarm one had to cope with people like you so they went bananas about telling witch state a contact should be named at...

in this industry normal sate is when the switch is at the ready state..so when the door contact is close to its magnet...

much easily said then all the bs you post....

Reply to
petem

now that the proof you didnt read the poster question properly....

"Robert L Bass" a écrit dans le message de news: OqSdnUv3LpV snipped-for-privacy@comcast.com...

Reply to
petem

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