eol resistors

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EOL resistors

racefanGuest

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12-19-2003, 02:29 AM

Can someone pls explain the purpose of an EOL resistor in an alarm system?How do they provide protection from tampering? Are they required orrecommended and why?

Thanks,Jay

SpikeGuest

Posts: n/a

12-19-2003, 03:00 AM

"racefan" wrote in messagenews:1guEb.89660$ea%.(E-Mail Removed) le.rogers.com...> Can someone pls explain the purpose of an EOL resistor in an alarm system?

It supervises the wiring to the detection device

> How do they provide protection from tampering?

EOL resistors http://www.electronicspoint.com/eol-resistors-t141995.htm

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Even if the system is not armed, tampering will be announced at the keypad.DEOL circuits provide even more info to the monitoring station. Notprofessional to dispatch police on a wiring problem :-)

Are they required or> recommended and why?

Don't be stupid. :-)

>> Thanks,> Jay>>

Rocky T. Squirrel, Esq.Guest

Posts: n/a

12-19-2003, 03:10 AM

To supply a known current flow in the loop circuit..A loss or increase in the current causes a switching circuit to triggereither a trouble or alarm signal.. Some really fancy loops also include a

diode to add a reverse current trigger as well.. (ie.. fire alarms, bellckts etc...)

hihcul

"racefan" wrote in messagenews:1guEb.89660$ea%.(E-Mail Removed) le.rogers.com...

> Can someone pls explain the purpose of an EOL resistor in an alarm system?> How do they provide protection from tampering? Are they required or> recommended and why?>> Thanks,> Jay>>


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racefanGuest

Posts: n/a

12-19-2003, 03:28 AM

Thanks guys. Makes sense now.I wasn't sure it was worth the extra soldering but obviously it is.

racefanGuest

Posts: n/a

12-19-2003, 11:32 AM

Thanks Robert. Good explanation. I read your FAQ but didn't pick up onthese details.Thanks for mentioning about NOT installing the resistors in the panel.That's what I wasplanning to do.

I still don't understand how the system can sense a short by using aresistor. If someoneshorts a door contact for example - as long as they use a jumper wire anddon't allowthe existing wires to leave the contact - the system won't know that's itbeen shorted, right?

Or is the idea that most won't know to do that or will most likely break thecircuit at somepoint.

"Robert L. Bass" wrote in messagenews vqdnf3Y-sqxGH-iRVn-(E-Mail Removed)...

> > Can someone pls explain the purpose of an EOL> > resistor in an alarm system? How do they provide

> > protection from tampering? Are they required or> > recommended and why?>> Hi Jay,>> Good questions. I have a FAQ page on EOL resistors that you may find> helpful.> http://www.bass-home.com/gotofaq.cfm?pg=eol_resistor>> EOL resistors allow a small trickle of current to flow through an alarm

> sensing circuit (zone). As long as the resistor is present the panel> registers this as a normal condition. In the case of a burglary zone ifthe


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EOL i t htt // l t i i t / l i t t141995 ht


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> circuit opens that's usually registered as an alarm condition. A short> circuit is a trouble condition. Fire alarm circuits are usually the> opposite. That is, an open circuit is a trouble and a short circuit is an> alarm condition.>> The EOL resistor is supposed to be installed at the sensor farthest from

the> control panel, ergo the name *end* of line. If a crooked employeeattempts> to short out a sensor that has a built-in EOL resistor at his employer's> store the control panel can send a silent signal to the central station> allowing them to notify the property owner. Likewise, if a zone is> accidentally shorted out while someone is working in the building thealarm> can display a trouble condition so they know there's a problem and can

> repair it.>> The above are by no means the only way to use an EOL resistor but they are> fairly common. One of the most common errors that alarm installer make is> to install the EOL resistors inside the alarm control panel. There they> serve no purpose at all and may as well have been programmed out and leftin> the poly bag in which they were shipped. If you plan to use EOL resistors> at all, be sure you install them at the point on the cable farthest fromthe

> control panel terminals.>> Regards,> Robert>> =============================>> Bass Home Electronics> 2291 Pine View Circle> Sarasota Florida 34231

> 877-722-8900 Sales & Tech Support> 941-925-9747 Fax> 941-232-0791 Wireless> Nextel Private ID - 161*21755*1> http://www.bass-home.com> http://www.bassburglaralarms.com> =============================>>>


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EOL resistors http://www electronicspoint com/eol resistors t141995 htm


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Rocky T. Squirrel, Esq.Guest

Posts: n/a

12-19-2003, 02:48 PM

fake-em out by using N.O. contacts..

wire-em in parallel instead of series..

"racefan" wrote in messagenews:KdCEb.92817$ea%.(E-Mail Removed) e.rogers.com...> Thanks Robert. Good explanation. I read your FAQ but didn't pick up on> these details.> Thanks for mentioning about NOT installing the resistors in the panel.> That's what I was> planning to do.>> I still don't understand how the system can sense a short by using a> resistor. If someone> shorts a door contact for example - as long as they use a jumper wire and> don't allow> the existing wires to leave the contact - the system won't know that's it> been shorted, right?> Or is the idea that most won't know to do that or will most likely breakthe

> circuit at some> point.>>> "Robert L. Bass" wrote in message> news vqdnf3Y-sqxGH-iRVn-(E-Mail Removed)...

> > > Can someone pls explain the purpose of an EOL> > > resistor in an alarm system? How do they provide> > > protection from tampering? Are they required or

> > > recommended and why?> >> > Hi Jay,> >> > Good questions. I have a FAQ page on EOL resistors that you may find> > helpful.> > http://www.bass-home.com/gotofaq.cfm?pg=eol_resistor> >> > EOL resistors allow a small trickle of current to flow through an alarm> > sensing circuit (zone). As long as the resistor is present the panel

> > registers this as a normal condition. In the case of a burglary zone if> the> > circuit opens that's usually registered as an alarm condition. A short


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EOL resistors http://www electronicspoint com/eol-resistors-t141995 htm


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> > circuit is a trouble condition. Fire alarm circuits are usually the> > opposite. That is, an open circuit is a trouble and a short circuit isan> > alarm condition.> >> > The EOL resistor is supposed to be installed at the sensor farthest from

> the> > control panel, ergo the name *end* of line. If a crooked employee> attempts> > to short out a sensor that has a built-in EOL resistor at his employer's> > store the control panel can send a silent signal to the central station> > allowing them to notify the property owner. Likewise, if a zone is> > accidentally shorted out while someone is working in the building the> alarm> > can display a trouble condition so they know there's a problem and can

> > repair it.> >> > The above are by no means the only way to use an EOL resistor but theyare> > fairly common. One of the most common errors that alarm installer makeis> > to install the EOL resistors inside the alarm control panel. There they> > serve no purpose at all and may as well have been programmed out andleft> in

> > the poly bag in which they were shipped. If you plan to use EOLresistors> > at all, be sure you install them at the point on the cable farthest from> the> > control panel terminals.> >> > Regards,> > Robert> >

> > =============================>> > Bass Home Electronics> > 2291 Pine View Circle> > Sarasota Florida 34231> > 877-722-8900 Sales & Tech Support> > 941-925-9747 Fax> > 941-232-0791 Wireless> > Nextel Private ID - 161*21755*1> > http://www.bass-home.com> > http://www.bassburglaralarms.com

> > =============================>> >> >


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>>

fly in the ointmentGuest

Posts: n/a

12-19-2003, 03:13 PM

racefan wrote in> I still don't understand how the system can sense a short by using a> resistor. If someone> shorts a door contact for example - as long as they use a jumper wire and> don't allow

> the existing wires to leave the contact - the system won't know that's it> been shorted, right?

It's true that if you short the contact AFTER the resistor, the system won'tdetect it. Some contacts are made with integral resistors so someonetampering can't get ahead of the resistor.js

RichGuest

Posts: n/a

12-19-2003, 09:25 PM

How about running four wire, and running the zone back to the panel andplacing the EOL resistor there in the locked box?

AegisGuest

Posts: n/a

12-19-2003, 09:33 PM

Nothing wrong with that at all that I can see... Uses more wire withoutbeing absolutely necessary though.

"Rich" wrote in messagenews:e5adnaQdFrZg536iRVn-(E-Mail Removed)...

EOL resistors http://www.electronicspoint.com/eol resistors t141995.htm

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>> How about running four wire, and running the zone back to the panel and> placing the EOL resistor there in the locked box?>>

JackcsgGuest

Posts: n/a

12-20-2003, 12:58 AM

Well since 22/4 is probably the only box of wire you purchase...good idea.

Jack

"Rich" wrote in messagenews:e5adnaQdFrZg536iRVn-(E-Mail Removed)...>> How about running four wire, and running the zone back to the panel and> placing the EOL resistor there in the locked box?>>

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