Alarm Supervision Guide

By: Ari Erenthal, Published on May 24, 2017

Burglar alarms can constantly monitor the health of attached circuits, sensors, and devices to ensure that they remain operational. This is known as supervision. Poor implementation of supervision is a common source of false alarms. However, if properly installed, supervision can reassure users that the alarm remains functional, and can alert installers to potential problems, allowing them to repair them. In this note, we examine alarm supervision, including

  • What is a supervised circuit?
  • Supervised vs unsupervised circuits
  • Getting the right resistance
  • Using resistors
  • Where to install the resistor
  • Insider threats
  • Implementation challenges
  • Using alarm supervision

What Is A Supervised Circuit?

A supervised alarm circuit or device is one that is constantly and actively checked by the alarm panel to ensure that it is still functional and responsive. It does this by reading the resistance on the circuit, and comparing it against a selected range. 

Alarm Supervision: Pro And Con

There are many reasons to use alarm supervision, including:

  • Some standards require supervision
  • Ability to bid on higher profit alarm jobs, such as UL listed alarms (jewelry stores, banks, etc)
  • Commercial fire alarms always require supervision
  • Ability to takeover supervised accounts
  • Supervised alarms can let alarm installer know when alarm is defective
  • If alarm is unsupervised, customer may be relying on broken alarm to protect premises

Some alarm companies never use supervision, or only use supervision for commercial applications but not residential ones. Key reasons include:

  • ****** ******* **** ********* takes ****** *** ** more *********
  • ******** ******** **** ***** ** resistors *** ********* *** must ** *******-*******
  • ************ *********** ******** ****** trained ***********
  • ** * ********* **** is *** ******** ***** away, ***** *********** *** become *****

*********** ***** ************* *** quickly ****** ************ ****** they *** ** ********* quickly *** ***********, *** highly ******* ***** ********** who ********** *** ** implement *********** ******* ****** ******** than **** *** ** not. *******, *** **** advantage ** *********** ** to ****** **** *** alarm ** ********** ********** and ******* ** ********** the ******** ** ***** it *** **** *********. For **** ******, ** is ****** *********** **** supervision ** **** ** every ****. 

Supervised ** ************ ********

** * ********** ******* opens, *** ********** **** go **** *** ********, causing *** ***** ** ** into ***** *********. *******, if *** ********** ******* goes******** ******** *** ** a *****, *** ***** goes *********** *********.

** ********, ************ ***** simply **** *** * closed *******, ***** **** alarm ********* **** ** the ******* *****.

** ********* *****, **** means **** **** *** circuit ** ************, *** panel cannot **** *** ********** between * ****** ****** and * ******* ****. *********, a clever ********* *** ******* to ***** * ****** by ******** *** **** running ** *** ******. This '******' *** ***** panel *** ****** *** adversary ** **** *** close *** ****** ******* setting *** *** *****. 

*** ********* ***** ************ how * ********** **** works.

Getting *** ***** **********

*** ********** ******** ** create * ********** ******* is ********* ** *** manufacturer. *** *******, ********* panels ******* **Ω (*,*** ohms), ***** ******** *.**Ω, and *** ******** **Ω. Because *********** ** ********* on *** ********** ***** ****** a ******** *****, ********** use * ****** ****** a******** ** ****** *** ********** is *******. * ******** ** * device **** **** * specific *** ********** ****** of ********** ** * circuit. * ******** ** a ******* ******, ***** means ** ****** ** adjusted ** ********** *** does *** *** ** output *******. **** ************* include a **** ** ********* with ***** ***** ***** sold. ********** ******** *** commonly ******* *.**Ω *** 3.2kΩ. 

*******-**** ********* **** **** long, ******** *****, ** opposed ** *******-***** *********, which *** ******** ** be ******** **** * PC *****. **** ****** alarm ********** ** **** the ******** ****** *** end ** *** *******, thus ****** *** ****** circuit * *****, ******** resistance *****. **** *** alarm ***** ***** *** circuit, ** **** **** all *** ********** *********** by *** ****, *******, and *******, **** *** resistor. 

********* **** ** ****** are ******** ** ********* (k) ** **** (Ω). For *******, * ******** that **** *,*** **** ** a ******* ** ***** as * **Ω ********. * resistor **** **** *,*** ohms ** * ******* is ***** ** * 2.2kΩ ********. 

*** ********* **** ***** bands ** **** **** they *** ***** ***. The **** ****** ****** is **** *****. *** *** colors ********** ** ******** numbers. *** ***** *** bands ******** *** ****** in ******, ***** *** then ********** ** *** third ****. *** ******* the resistor ** *** ***** has a *** ****, ******* 2, * ***** ****, meaning *, ****** ** 20, *** * *** band, ******* ** ** multiply *** ****** *****, making ** * ***Ω resistor. *** ***** **** indicates *** ********* ** the ********. **** **** is ****, ***** ********* a ********* ** ±*%. Resistors *** ******** **** in ******* *****, ***** without ******, ** ******* which ******** ** *** pack ** *** ******* one ** ****** ** know. ********* *** ** purchased from ***** ***** *** electronics ****** ******. 

Using *********

*** ***** ********** ******** for *********** ******* **** manufacturer ** ************. ***** panel ************* ******** ******* their ***** ****** **** resistors. Different ***** ************* ******* different ******** ******, ** alarm ********* **** **** a **** ** ********* alarms **** ******** ************* may **** ** **** a *** ** **** for ******* *****. 

**** ****** **** * feature ********** ********. **** ***** **** doubling, ** ********* *** run *** ***** ** wires ** * ****** set ** ********* ** the ***** *****. ** the *** ** **** pair ** ***** **** be * ********* ***** resistor. *** ***** *** identify *** **** ****** based ** *** **** ** resistance ****. 

Where ** ******* *** ********

********* ****** ****** ** ** the ***** ** *** circuit **** ** *** furthest **** *** *****. This ** ***** ***** *** ** *** line. **** ***** ***** manufacturers ***** ** ********* used **** *** ** end ** **** *********, or *****. 

*** **** ****** *********** method ******** ********** *** ******** to *** ** *** ********* of * ****** ** device. **** ** ************ effective ** ***** ** a ****** ****** ** the ****, *** ** there ** **** ****** the ****** *** * resistor. *** *******, * glassbreak ** ****** ******** can ****** *********** * resistor, *** ***** ******* are ***** ***** ** their *** ****. 

******** ******** *** ***** wired ** ****** **** other ********. *** *******, if ***** *** ******* windows **** ** **** other, ** ********* *** choose ** **** *** the ******** ********, ** that *** *** ******* share *** **** ****. In ***** *****, *** resistor **** ** ** the *** ** *** line, ***** ** ** say, *** ***** ** the **** ******** **** the *****.

**** ******* ***** ******** contacts **** ******** ****** that *** *********** * resistor. *** ******* ********, which *** ***** *** unobtrusive, ** *** **** with ******** ****** *** cannot **** * ********. Installing * ******** ** a ***** ***** ******** contact ** **** ******* can ** ***** *********** as ****. ** ********** an *** ** **** resistor **** ** *********, an ********* *** ****** to *** *** **** wire ******, ***** ****** the ******** ** ** installed ** *** ***** instead ** ** *** field (** ** *** sensor ** ******).  

******** ******** **** *****-** resistors *** **** ********* to ******** **** ******* manufacturers **** ** *** and **********. ******* ** the ********** ************ ****** from ************ ** ************, these ********* *** ***** *** stocked ** ***** ********* and **** ******* ** special *******. **** *** contact ******** **** *** panel *** **** * built-in ********. ***** **** than *** ******** ** a *******, ** ******* the ******** ** *** wrong ****, **** ******* the ***** ***** **** *********** the *******. 

Insider *******

******* ******, ** ***** nature, ******* ********** **** threats ** *** ******* of *** ********* ****. However, ** ** **** difficult ** ******* ******* threats ** *** ****** of *** ********* ****, especially ** ***** ******* can ****** *** ********* while *** ***** ** disarmed. ********* *** **** to ***** ** ****** in * ***** **** their ********* **** ****** of **** *** *********** to ***** *** ******* alarm, ******** *** **** *****, and ******** ** ******* the ***** ** **** it **** ** ****** to ****** * *****-** after *****. ***** *********** is *** *** ***** installers ****** ******* ***** insider *******.

** ** ******** ****** a **** ** "*****" a ******* ****** *** day, ********* ** **** back *** ****** *** place ** *****, *** alarm **** **** * trouble ****** ** *** keypad, ****** * *********** party *** *********** ** investigate *** ***** *** source ** *** *******.

Implementation **********

*********** **** ** ***** step ** ****** ******, and ********* *** ** tricky ** **** ****. It ** ***** ********* to *** ********* ** low ******* ******** ******** and ***** ***** ********. Magnetic ******** **** ***** in ********* *** *********, but **** *** **** expensive **** ******** ********. However, *** ******* ********* is *********** *****, *******, the *** ** *** line ******** **, ********** when ****** **** *****. *********** the ******** ***** ******** either *********** ***** ****** or ********* ********** **** a ***** ***** *** fact.  

*** **** ****** ****** of ********* ** *** exact ********* ** *** resistor. ********* **** ** placed ** *** ******** point ** *** ****, which ** ** *** device. ** **** ** placed ****** *** ********, not ****. ** * resistor ** ****** ****** *** end ** *** ****, anything ******* **** **** be ************, *** ** a ******** ** ****** across *** ********* ** the **** ******, ** will ******* *** **** from *******.

 

Comments (13)

The picture on the right is mistakenly labeled 'incorrect'. If this is an "Open Circuit device" such as Foot pedal, Money clip, etc. it is in the right place. Secondly, not often but it has happened,  manufacturers will label a device as to the condition of the relay when activated, therefore this is correct as well.

Yes, that would be true if it were an NO device, but it's actually an NC device. 

Most modern powered detection devices with "NC" and "C" are closed loop (or Normally Closed), so in that case it would be incorrect.

 

The picture with same device where resistor is properly placed, I would have incorporated the tamper:

green on 1st "T", one leg of resister on 2nd "T", other leg of resistor on "C" and white on "NC"

Great point! But I actually wanted to address tampers in a separate guide. 

Here we often use double end of line (DEOL) to allow for both alarm & tamper conditions on a single pair. It allows tamper monitoring 24/7 for both sensor housing & cable tamper along with alarm monitoring only when system is armed

 

Another great article, Ari!

You have touched upon one of pet gripes: the failure of installers to place EOL resistors where they belong - at the end of the line. I just completed a survey of 32 commercial sites that had intrusion alarm systems installed by a variety of alarm companies. In nearly every case, the resistors were at the panel. The exception was a multiplexed system that used zone expanders out in the field. In this case, the resistors were at the zone expander, not at the device. Same problem.

I consider this practice to be negligence on the part of the installer. In jobs we specify, we always verify that EOL resistors are properly installed and will make the installer rework the job if it isn't right.

Looking for your article on tamper switches, another one of my pet peeves. I did a short article on the topic myself a short time back.

In jobs we specify, we always verify that EOL resistors are properly installed and will make the installer rework the job if it isn't right.

Michael, do you explicitly call this out in the RFP itself? I am curious what level of detail you include.

Within each RFP,  I have a specification section called "Basic Materials and Methods" that includes detailed requirements for conduit, cabling, fasteners, and installation techniques.

The paragraph that addresses EOL resistors typically reads something like this:  

"Install end-of-line resistors at each detection device as per manufacturer.'s installation instructions. End-of-line resistors shall be connected to flexible wire leads and protected with heat-shrink tubing or equivalent. End-of-line resistors shall be installed at the final connection point nearest to the device unless specifically noted otherwise. End-of-line resistors shall not be installed at the control panel, input board, or zone expansion module."

Well, I guess you can't do it right if you were never shown the right way to do it. 

Poor training is often an issue, but I also expect installers to take the time to fully read the installation and programming manuals for the equipment they are installing. 

Good eye. I needed that resistor for another device, so I couldn't use a permanent splicing method. I realized my mistake when I tried to take the resistor off my magnetic contact. In the old days, you could just run to Radio Shack and buy a fistful of resistors for a couple of bucks, but not anymore. 

Read this IPVM report for free.

This article is part of IPVM's 6,534 reports, 880 tests and is only available to members. To get a one-time preview of our work, enter your work email to access the full article.

Already a member? Login here | Join now

Related Reports

Forced Door Alarms For Access Control Tutorial on Aug 17, 2020
One of the most important access control alarms is also often ignored....
Exit Devices For Access Control Tutorial on Aug 25, 2020
Exit Devices, also called 'Panic Bars' or 'Crash Bars' are required by safety...
Drain Wire For Access Control Reader Tutorial on Sep 23, 2020
An easy-to-miss cabling specification plays a key role in access control, yet...
AHJ / Authority Having Jurisdiction Tutorial on Aug 06, 2020
One of the most powerful yet often underappreciated characters in all...
Use Access Control Logs To Constrain Coronavirus on Apr 09, 2020
Access control users have included capabilities that are not commonly used...
Avigilon Social Distancing Analytics Tested on Aug 26, 2020
Avigilon released its social distancing analytics in response to the...
JCI / Tyco Security Products Layoffs on Jun 05, 2020
Johnson Controls / Tyco Security Products has confirmed COVID-19 related...
Door Fundamentals For Access Control Guide on Aug 24, 2020
Doors vary greatly in how difficult and costly it is to add electronic access...
Vehicle Gate Access Control Guide on Mar 19, 2020
Vehicle gate access control demands integrating various systems to keep...
U.S. Government Accountability Office Urges Facial Recognition Regulation on Aug 27, 2020
The US Government Accountability Office (GAO) is urging facial recognition...
ZKTeco Presents SpeedFace Recognition + Body Temperature Detection on Apr 21, 2020
ZKTeco presented its SF1008+ reader with body temperature and face mask...
Seek Scan Thermal Temperature Screening System Tested on May 28, 2020
Now that IPVM has tested Dahua, Hikvision, and Sunell, we are returning to...
Hazardous & Explosion Proof Access Control Tutorial on Feb 27, 2020
Controlling access to hazardous environments requires equipment meeting...
FDA Defines Correct Operation of "Fever Cameras" on May 26, 2020
The US FDA has now defined the correct operation of "Thermal Imaging...
Remote Network Access for Video Surveillance Guide on Jul 27, 2020
Remotely accessing surveillance systems is key in 2020, with more and more...

Recent Reports

OnTech Smart Services Partners With Google and Amazon To Compete With Integrators on Sep 25, 2020
A pain point for many homeowners to use consumer security and surveillance is...
The Future of Metalens For Video Surveillance Cameras - MIT / UMass / Immervision on Sep 25, 2020
Panoramic cameras using 'fisheye' lens have become commonplace in video...
Hikvision Sues Over Brazilian Airport Loss on Sep 24, 2020
Hikvision was excluded from a Brazilian airport project because it is owned...
China General Chamber of Commerce Calls Out US Politics on Sep 24, 2020
While US-China relations are at an all-time low, optimism about relations...
Verkada Disruptive Embedded Live Help on Sep 24, 2020
Call up your integrator? Have someone come by the next day? Verkada is...
IP Networking Course Fall 2020 - Last Chance - Register Now on Sep 23, 2020
Today is the last chance to register for the only IP networking course...
Drain Wire For Access Control Reader Tutorial on Sep 23, 2020
An easy-to-miss cabling specification plays a key role in access control, yet...
Norway Council of Ethics Finds Hikvision Human Rights Abuses "Ongoing" on Sep 23, 2020
Hikvision's involvement in "serious human rights abuse" in Xinjiang is...
IPVM Camera Calculator User Manual / Guide on Sep 23, 2020
Learn how to use the IPVM Camera Calculator (updated for Version 3.1). The...
Installation Course Fall 2020 - Save $50 - Last Chance on Sep 22, 2020
This is a unique installation course in a market where little practical...
SimpliSafe Business Security Launched Examined on Sep 22, 2020
SimpliSafe has launched "SimpliSafe Business Security" that the company...
FLIR CEO: Many New Fever Entrants "Making Claims That The Science Just Won't Support" on Sep 22, 2020
FLIR's CEO joins a growing number calling out risks with fever / screening...
China Bems Temperature Measurement Terminal Tested on Sep 22, 2020
Guangzhou Bems (brand Benshi) is the manufacturer behind temperature...
Axis Exports To China Police Criticized By Amnesty International on Sep 21, 2020
Axis Communications and other EU surveillance providers are under fire from...
Milestone XProtect on AWS Tested on Sep 21, 2020
Milestone finally launched multiple cloud solutions in 2020, taking a...