IP fire systems

The Internet, with its inherent capabilities and advantages, has impacted all aspects of electronic communications, including many applications in the security arena. Everyone is aware of the huge impact IP communications has had on the security video market, for example, but the impact can also be felt in the fire and life safety sector.

About 10 years ago, there was a feeling that IP technology would not make any real headway into the Fire/Life Safety market. Among the reasons were concerns of being able to comply with strict fire codes, which did not address/allow the use of the Internet to monitor Fire Systems. The code also required that the fire and supervisory alarm must reach the central station after initiation within 90 seconds. (In NFPA 72, fire alarms are referred to as "fire signals" and the central station is referred to as a "supervisory station." In this article, I will use the terms "fire alarms" and "central station.")

The code forced users to install a dedicated phone line, a backup phone line and a phone line detection/automated switch to be incorporated into each panel to ensure fast and reliable communications. The phone lines were analog, powered by the phone company (POTS lines). NFPA 72 also required the Digital Alarm Communicator Transmitter (DACT) is to send its signal over the Public Switched Telephone network. In the recent past, the phone companies across the nation have been trying to get rid of POTS lines. In many fire alarm applications today, the "phone line" is actually part of a digital network.

How the PC Changed Alarm Monitoring

Manufacturers of large-scale fire systems started adding IP-based communication capabilities to intelligent fire panels to improve market value. Initially, the Internet was used as a way to view many different alarm panels at one location on a PC. Several fire system manufacturers sold a software package that enabled viewing status/trouble alarms, as well as fire and supervisory alarms at a PC and a UL alarm-monitoring center. This capability was added, while allowing the field fire system to continue to exist as it always had with standalone functionality and dual phone monitoring.

In this configuration, the fire alarm panel connected to an alarm monitoring UL central station via analog phone lines for approved alarm monitoring and dispatch of a local fire department. The initiating devices and annunciating appliances were connected directly to the fire panel in the traditional field wiring methods. There was an automatic fire panel evacuation capability and the fire panel operated just like it had for years - as a complete standalone system. The only difference was an IP connection that allowed the intelligent fire panel's status and any alarms to be viewed on a PC, which was not for the purpose of primary response.

The PC did, however, provide many benefits. For example, if a smoke detector was getting dirty and needed to be cleaned, the person viewing the fire panel via a PC would have an early warning that the specific detector needed cleaning. Also, the person viewing the PC could look at several fire panels across many different locations and provide maintenance insight and overview via trouble alarms. Lastly, the PC capabilities provided a central location to download software into a remote fire panel to speed up the installation process and help standardize the software residing in the different fire panels.

One negative to this approach was that the software used in the PC to communicate with the fire panel was proprietary, which required the installed fire panels to be from the same manufacturer. This approach worked well, but was primarily used on large-scale intelligent fire systems.

Adding IP Communications

Now, many fire alarm panels have an IPDACT module that can send fire alarms via the Internet to an approved UL alarm monitoring central station. To complete the IP communication from the fire panel to the UL-approved alarm monitoring central station, an IP-compatible receiver is required, which enables the central station to monitor fire alarms and dispatch a local fire department just like they would with the dual phone line fire alarm communication approach. The IP-compatible receiver enables different fire panels to send a fire alarm, supervisory alarm and a trouble alarm via the Internet.

The IPDACT communicating fire panels use a standardized protocol defining these alarms as they did in the past over POTS lines, but now they do so over the Internet. These alarms may also be encrypted, which is allowed under UL standard 864 (9th edition). This edition was written several years ago, but became effective on Dec. 31, 2008. The International Fire Code (IFC), Uniform Fire Code (UFC), Uniform Building Codes (UBC), NFPA and various jurisdictions across the country must accept the new UL edition before it applies to a given location. From a practical standpoint, it will take time, even years for this to happen. Therefore, the actual impact and time schedule for acceptance at a specific jurisdiction is difficult to predict. Many municipalities within close proximity often standardize on different versions of the IFC or UFC, which can make installing IP-based fire systems more difficult.

The 9th edition of UL 864 reduces the 90-second alarm/signal-reporting requirement (found in NFPA 72) to 10 seconds. If the IP connection is tested and operational at each 10-second verification increment, the fire panel can reliably send an alarm to the alarm monitoring UL central station within the 10-second code requirement. With a POTS line configuration, the supervision was verified every 24 hours and there was a backup analog phone line. The panel would switch from one phone line to another when there was no dial tone detected. Under the dual dedicated phone line approach, the panel would also report any phone line problem it detected to the alarm monitoring UL central station, by using an operational phone line.

IP Communication Advantages and Issues

There are several advantages of using an IPDACT and the Internet to communicate. One advantage is that dedicated phone lines and the their cost are no longer required. A second is that existing systems can remain in place and an IPDACT can be added on, reducing the cost of replacing an existing fire panel to use the IP communication approach. Thirdly, the IPDACT accept dynamic and static IP addressing reduces some installation issues for the IT department. Another advantage is that the IPDACT can communicate to two or more receivers, which provides a level of backup. Finally, the receiver is checking the fire panel frequently.

Despite the advantages, there are three issues that must be considered:

1. The local AHJ must approve the IP fire installation.

2. The network components supporting the Internet may or may not have battery backup, which historically was not a problem with the dual phone line method. In the 2010 edition of NFPA 72, all equipment necessary for transition of alarms to the central station must have the same secondary power capacity as the fire alarm panel.

3. It is unlikely that the hubs, routers and switches encountered between the fire panel and the alarm monitoring UL central station are approved for fire alarm processing.

IP Technology for Fire Systems

In addition to the IPDACT fire modules, there is newer IP fire alarm equipment now available that breaks down the standard fire panel into modules that are interconnected via an IP structure. For example, there would be a module or modules that the initiating devices and/or annunciating appliances connect to using traditional fire monitoring/supervisory schemes. One module provides display information, meaning that a system might be composed of display modules, analog loop signaling device modules, notification appliance modules and power modules all connected via CAT 5 cable. The approach uses the various functions that are often part of a single circuit board within the fire alarm panel and breaks them apart to make the installation effort easier by reducing long wire runs by using an existing IP network. These separated modules combine electronically via IP and can be referred to as a virtual fire alarm panel.

The obvious advantage of separating functionality into modules would be flexibility. For example, additions and changes to the fire system could easily be made without regard to the existing fire panel size and available points. Long wire-pulls bringing everything back to a central point would be eliminated. A single-point failure would be minimized with the distributed intelligent modules used in this approach.

IP Deployment Challenges

One of many questions that might arise in an IP fire system deployment is the need for CAT 5 red fire cable to provide inter-conductivity, because everyone knows fire cabling is red. There are also very real concerns about reliability, maintenance, etc., with the intranet approach used within a given installation. For example, the IT department will argue that their system is virtually always up and operating; however, the problem is that there will always be situations when a router, hub, switch is taken down for maintenance or other reasons. These down times can cause a communication lapse greater than 90 seconds and certainly greater than 10 seconds.

An additional challenge for any IP-based fire alarm system is the ownership of the IT network that exists in many facilities. The IT department in most companies works under the primary tenant that key corporate mission-critical computer programs/functions must operate no matter what. Many IP applications, for example, are considered secondary to mission critical corporate functions. E-mail is an important function, but if it takes five minutes to receive an e-mail because of a router being down for maintenance, it is not a big concern for the IT department.

For this reason, an IP fire system installation will require an IT commitment and thorough understanding of the importance of a fire system to the corporation, because fire systems have not typically been part of their concern in the past. The expanding use of IP fire systems, security and life safety alarm systems will require a stronger link between Security and IT.

Robert Pearson holds a BSEE and is a Registered Professional Engineer. He has been an instructor at George Washington University teaching "Integrated Security Systems" and "Corporate Security Management," has written numerous articles for various technical magazines and has recently published a book entitled "Electronic Security Systems." On a day-to-day basis he oversees design, project management, and maintenance of security systems for multiple sites. Mr. Pearson is a member of A/E National Standing Council for ASIS International.

 

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