Using Ethernet and Networks for Fire Alarm and Emergency Communications Systems

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Wayne D. Moore, P.E., CFPS, SET Hughes Associates, Inc.

1 Using Ethernet and Networks for Fire Alarm and Emergency Communications Systems Speeding into the 21 st century? Or Not? Wayne D. Moore, P.E., CFPS, SET Hughes Associates, Inc. 117 Metro Center Boulevard, Suite 1002 Warwick, RI

2 Issues Raised During NFPA Cycle Questions concerning the acceptability of using Ethernet connections and other non-fire or non-mns networks for fire alarm and signaling systems applications are being raised more and more.

3 NFPA The 2013 edition of NFPA 72 includes a new designation for shared pathways in This section does not define any performance or installation requirements.

4 NFPA Currently the code doesn t address Ethernet use beyond in combination systems (23.8.4), connections to other non-fire systems ( ), MNS interface with other systems ( ) and supervising station transmission off site using IP networks ( )

5 Additional Concerns Some of the concerns that were raised during related discussions for the 2013 edition included: - Ground detection & effects, - Shorts on the circuits, - System management, - System availability, - Software control, and - Testing and maintenance.

6 Networks Task Group Formed The NFPA 72 Correlating Committee established a Task Group to address the issues and develop proposals for the 2016 edition of the Code

7 CC Task Group Wayne D. Moore, P.E., Chair Richard Roux, NFPA Liaison A.J. Capowski, Tyco Aviv Siegel, Athoc Paul Crowley, FM Robert Elliott, FM Larry Shudak, UL Dan Horon, Cadgraphics Vic Humm, P.E. Michael Pallett, Telecor Jeff Silveira, BICSI Efraim Petel, Alerting Solutions Joe Collins, DFW Charles Pugh, DFW

8 NFPA 72 Networks TG Charge Proposed Scope for Networks Use in FA/ECS: Develop language for use in Chapters 12 and 24 that will address the use of Ethernet and Local Area Networks (LAN) and Wide Area Networks (WAN) in fire alarm systems, fire EVACS and mass notification systems. Language to specify the type of network acceptable, reliability required, listings if any and use of the network to connect devices or appliances or interfaced systems. Failure modes shall be considered and addressed when developing the application and installation requirements. Language shall be developed for operational integrity and acceptable end-to-end communication verification and conductor integrity.

9 Creating Common Ground The following slides were created to illustrate the different technologies, and their properties when used in today s alarm systems. A presentation will be given to each Technical Committee that will vote on proposals related to Ethernet.

10 Approved Fire Alarm Pathway One familiar type of Class B pathway has wires with direct current, and a resistor at the last device. The end-of-line resistor offers a level of assurance that the all wires are connected to the intended device. FACP Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

11 Approved Fire Alarm Pathway If a short occurs at any point on a Class B notification appliance pathway, the entire circuit becomes inoperable. FACP X Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

12 Approved Fire Alarm Pathway If an open occurs at any point on a Class B initiating device circuit, every device thereafter is inoperable. This is true even when a smoke detector is removed for maintenance. FACP Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

13 Approved Fire Alarm Pathway Class B pathways report a single ground connection because, a second ground may connection occur at some point later, and act like a short-circuit. On a Class B IDC, a short-circuit means alarm! FACP Wire touching ground Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

14 Approved Fire Alarm Pathway Class B pathways report a single ground connection because, a second ground connection may occur at some point later, and act like a short-circuit. On a Class B IDC, a short-circuit means alarm! FACP Two wires touching ground Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

15 Approved Fire Alarm Pathway Class B pathways report a single ground connection because, a second ground connection may occur at some point later, and act like a short-circuit. And, on a Class B IDC, a shortcircuit means alarm! FACP Two wires touching ground Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

16 Approved Fire Alarm Pathway The Class B, multi-drop signaling line circuit gives each device a numerical address, and the control unit can communicate with all attached devices on just two wires in parallel. FACP Multi-drop Communications 101 Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

17 Approved Fire Alarm Pathway An open on a Class B multi-drop SLC reports a trouble if the control unit cannot communicate with every device. FACP X Multi-drop Communications 101 Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

18 Approved Fire Alarm Pathway Shorting the two wires at any point stops communication with every device. Not an indication of alarm as with an IDC, a short on the Class B multi-drop SLC reports a trouble. FACP X 101 Multi-drop Communications Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

19 Approved Fire Alarm Pathway While every device is attached to the same two wires, a single ground reports a trouble. But, the single ground is not allowed to impact communications. This feat of software protocol engineering is an accomplishment to be proud of. FACP Multi-drop Communications 101 Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

20 Approved Fire Alarm Pathway A second ground on a Class B, multi-drop signaling line circuit stops all communication, as it is a short-circuit. FACP Multi-drop Communications Version 2 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

21 Protocol comparison Typical fire alarm loop protocol has checksum validation, confirmation of alarms, and retry capability - Proprietary, company specific, small installation base In TCP/IP, these guaranteed delivery services can be governed by proven, public methods driven by the Internet Activities Board. Largest deployed protocol in the world Public, standards driven

22 Proposed Fire Alarm Pathway Network equipment can be thought of in two basic categories: Endpoints and Forwarding Equipment. Endpoint Forwarding Endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

23 Category 5 Ethernet Cable In between Endpoints and Forwarding Equipment, a standardized cable is used. Cat 5 is an example. Transmit Endpoint generates Receive or acts on alarm events IEEE requires galvanic isolation on each pair of wires Transmit + Transmit - Receive + Receive - Forwarding Network hub or switch that forwards data to endpoints IEEE requires galvanic isolation on each pair of wires Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

24 Category 5 Ethernet Cable Each Cat 5 cable is galvanically isolated at each end, inside the equipment. The isolation helps prevents transient grounds and shorts on one cable from affecting other components. Transmit Endpoint generates Receive or acts on alarm events IEEE requires galvanic isolation on each pair of wires Endpoint generates or acts on alarm events Transmit + Transmit - Receive + Receive - Cat 5 Cable Four wires are used for data transmission Forwarding Network hub or switch that forwards data to endpoints IEEE requires galvanic isolation on each pair of wires Forwarding Network hub or switch that forwards data to endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

25 If Transmit and ( ) or Receive and are shorted together, communication stops. In fire alarm systems, a fault condition must be reported within 200 seconds. Transmit Receive IEEE requires galvanic isolation on each pair of wires Transmit + Transmit - Receive + Receive - X IEEE requires galvanic isolation on each pair of wires Endpoint generates or acts on alarm events Forwarding Network hub or switch that forwards data to endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

26 A ground connection on any one signal wire does not block communication. IEEE requires isolation at each end of every Cat 5 cable. Every data packet is checked for errors and re-transmitted until verified. Transmit Receive IEEE requires galvanic isolation on each pair of wires Endpoint generates or acts on alarm events Transmit + Transmit - Receive + Receive IEEE requires galvanic isolation on each pair of wires Forwarding Network hub or switch that forwards data to endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

27 A second ground connection, on the other wire of a matched pair, will impair communication if it causes a short. A fault condition must be reported within 200 seconds. Transmit Receive IEEE requires galvanic isolation on each pair of wires Endpoint generates or acts on alarm events Transmit + Transmit - Receive + Receive IEEE requires galvanic isolation on each pair of wires Forwarding Network hub or switch that forwards data to endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

28 Again, each Cat 5 cable is galvanically isolated. Grounds and shorts have no direct path of electrical connection to other equipment or devices. Transmit Receive IEEE requires galvanic isolation on each pair of wires Endpoint generates or acts on alarm events Transmit + Transmit - Receive + Receive Endpoints IEEE requires galvanic isolation on each pair of wires Forwarding Network hub or switch that forwards data to endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

29 Here Good you network can see design a potential prevents vulnerability. a fault on any If a single cable path were from making to become more impaired, than one multiple device data inoperable. endpoints would not communicate with essential equipment. Endpoint Forwarding Endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

30 A proposed Class N path would require alternate communication pathways whenever more than one device would be impacted by a fault. Endpoint Forwarding Equipment Endpoints Version 1 Dan Horon 2013 DanHoron@RescueLogic.com Permission required for distribution.

32 TG Goal: Balancing Reliability, Risk and Speed Prescriptive Requirements vs. Performance Requirements

33 There is no Easy Button but the TG is working Diligently! Questions? Reliability Risk and Speed With Special thanks to Dan Horon for permission to use his slides

Agenda Technical Committee on Protected Premises Fire Alarm Systems June 25-27, 2014 La Jolla, CA

Agenda Technical Committee on Protected Premises Fire Alarm Systems June 25-27, 2014 La Jolla, CA Item No. Subject 14-6-1 Call to Order (8:00 A.M) 14-6-2 Roll Call 14-6-3 Approval of Agenda 14-6-4 Approval