Network technology is quickly consuming every aspect of life. From the television we watch, the news we read, to the computers we use each day, network architecture and Internet protocol (IP) addressability is fast becoming the preferred method of communication across the land. According to Section 3.3.156 of NFPA 72, 2010 Edition, Network Architecture is defined as, “The physical and logical design of a network, and the inherent ability of the design to carry data from one point to another.”
This month, we’ll take a look at how network technology is being put to good use in life safety. Possible areas of deployment include signal communications between fire alarm systems and central monitoring stations. We’ll also touch on the dissemination of signals along with how network technology promises to keep mass notification networks up to date. This includes the mass notification systems (MNS) fire technicians install and service.
Technology Creates Controversy
Network technology, as detailed under NFPA 72, 2010 Edition, carries the spark that powers many of today’s robust fire/life-safety systems. ©iStockphoto.com/Peter Austin
Traditional network technology may not be suitable for life-safety systems for a variety of reasons. Nevertheless fire alarm control panel manufacturers have incorporated many of the ideas and precepts used in traditional networks. The result is a more dependable, easy-to-install fire alarm system compared to those that utilize conventional technologies.
A good example of this is the E3 Series fire alarm system manufactured by Gamewell FCI, a Honeywell company. The E3 Series system uses a unique, 625kbps ARCnet broadband communication network as a backbone between alarm panels, controllers, I/O modules, relay boards, intelligent power supplies and smart expansion panels.
This broadband network is capable of utilizing metallic cable (two conductors twisted) as well as fiber-optic cable, or a combination of both. A single set of twisted wires is capable of carrying device data as well as voice information for emergency voice/alarm communications (EVAC) systems.
Best of all, instead of the typical 300- to 350-foot limitation imposed by traditional network technology, ARCnet is capable of supporting up to 3,000 feet of metallic wire between nodes. This arrangement makes it possible to eliminate miles of copper in a large building, thus saving time and money in labor and materials.
Campuses Often on Cutting Edge
One of the leading markets facilitating fire/life-safety communications across IT networks has been college campuses.
For example, a few years ago a college local to me in the Akron, Ohio, area brought in an electrical contractor to install Category-5e cable between a series of network racks and the fire alarm panels in key buildings on campus. A second firm was also hired to install communication equipment designed to interpret digital data from alarm panel DACTs, thus converting it to IP-based network communications, suitable for transmission over traditional wide area network (WAN) technology.
The idea was, and still is, to eliminate copper telephone lines — also referred to as Plain Old Telephone System (POTS). Instead of running DACT-based signaling through POTS, this college had it in mind to send the same data in a suitable IP format to a remote monitoring facility hundreds of miles away, and this they did.
There was a day not so long ago when no one in their right mind would have thought of using a traditional WAN, such as the Internet, to send critical life-safety signals from fire alarm panel to a central monitoring or supervising station. But the fact is, today, the NFPA 72, 2010 Edition appears to support this method of signaling.
Code Condones Network Use
In years past, NFPA 72 supported the use of the Public Switched Telephone Network (PSTN) as a primary means of signal transport. All sorts of technologies sprung up in the meantime, most of which were supported by the 2007 Edition. Today, however, the 2010 Edition fully supports the use of network technology, so long as it meets an entirely new set of rules regarding supervision.
To put it briefly, it appears that POTS may be set to go to pasture. “Public switched telephone network facilities shall be used only as an alternate method of transmitting signals” (Section 220.127.116.11.1.2, NFPA 72, 2010). Given the fact that fire alarm technology has moved into the network realm itself, I think it’s safe to say that the committee’s decision regarding PSTN is quite in line with what all of us know must come.