QUESTION: Can the Internet be used for monitoring of alarm signals? If so does it have a UL listing yet?
ANSWER: The use of the Internet to monitor burglary and fire alarm signals has become
an important and timely issue. Underwriters Laboratories (UL) has had several
ad hoc meetings, called the Industry Advisory Council, on the subject of Internet
monitoring for burglar alarm signals. This also includes the use of a company's
own internal network (i.e. intranet). The technology is referred to as "Packet
Data Switching Networks."
To explain UL and NFPA's involvement, UL has sole jurisdiction of burglar alarm signal standards. While NFPA 72 writes code for fire alarm signaling, UL uses its standard UL 864, Control Units for Fire-Protective Signaling Systems, to list fire alarm control panels, communications methods and central station equipment designed to NFPA 72. (More on the fire alarm side later.) After setting some basic guidelines, UL's Burglary Council directed UL to explore this technology and, if possible, proactively set an appropriate standard.
Whether monitoring is done using a proprietary central station on a second party, there is a drastic reduction in telephone line charges. This is especially true when you consider using this technology for fire alarm monitoring, since NFPA 72 requires two telephone lines when using digital alarm communications transmitters (DACT). The use of a company's intranet facility for alarm signaling is very cost-effective, as opposed to a second phone line.For others, the use of broadband facilities, such as DSL and cable modems, makes the use of an already existing broadband facility very attractive and cost effective, even when this service is procured only for fire alarm signaling.
During the Industry Advisory Council meetings, UL asked the industry, installing companies, manufacturers and consultants, for help in establishing a standard for intranet and Internet monitoring. The result was a UL bulletin setting the minimum requirements.
On the fire alarm side, UL deferred to NFPA. The Technical Committee On Supervising Station Fire Alarm Systems of NFPA 72 discussed this technology during the last cycle and concluded that it could be used as a primary and sole communications path for fire alarm signaling. This was allowed as a Technical Interim Amendment for the 1999 issue and appears in the 2002 issue under Other Transmission Technologies. While actually not named per se, changes to the code allows its use.
The NFPA committee needed to decide how to handle equipment used for network signal routing and how to deal with the requirement for prioritization of fire alarm signals over a network that does not prioritize any signals. The result was a Formal Interpretation (FI) that all equipment in the signal path must be listed or otherwise approved by a national testing laboratory "for the purpose." Fire alarm equipment must, therefore, be listed for "fire alarm use" and shared on-premises communications equipment must be listed for "the requirements applicable to communications network equipment." Additionally, a Tentative Interim Amendment (TIA) gave an exception to the prioritization requirements if end-to-end signal delivery timing is less than 90 seconds.
Several companies have listed equipment for both burglary and fire alarm signaling to meet these requirements. This technology allows for extremely fast signaling, while maintaining levels of supervision conforming with UL's definition of "line security" not possible with DACT and favorably comparing with very expensive active multiplex systems and two way radio systems.