Chapter 3 of NFPA 731 contains general definitions used in the standard. It is important to understand the different types of “Systems” referred to in NFPA 731.

There are many types of Systems mentioned in NFPA 731. A System is different than a Device but some of the definitions below also include the “System” or “portions thereof”.

For example: A Duress Alarm System is a system or “portion thereof” that connects to the duress alarm initiating devices whereas, a Duress Alarm Initiating Device is an initiating device intended to enable a person at protected premises to initiate a signal indicating a need for assistance. See below for the different types of Systems covered in NFPA 731.

Below is a sample of NFPA 731. For the complete section, see the actual NFPA 731 text at NFPA.ORG. Once there, click on the free access link to the latest edition of NFPA 731.

3.3.27 System.

3.3.27.1 Combination System (as related to premises security). A system that provides premises security as a portion of a single control unit, or multiple control units that work together to provide one integrated control.

3.3.27.2 Digital Imaging System (DIS). A video system in which a digital video signal travels from the camera and can be viewed by any authorized user at or away from the protected premises.

3.3.27.3 Duress Alarm System. A system or portion thereof that connects to duress alarm initiating devices.

3.3.27.3.1 Private Duress Alarm System. A system or portion thereof in which the action to activate the duress signal is known only to the person activating the device.

3.3.27.3.2 Public Duress Alarm System. A system or portion thereof in which the ability to activate a duress signal is available to any person at the protected premises.

3.3.27.4 Holdup Alarm System. A system or portion thereof that connects to holdup alarm initiating devices.

3.3.27.5 Integrated System. A control unit that includes other types of systems in addition to the premises security system.

3.3.27.6 Premises Security System. A system or portion of a combination system that consists of components and circuits arranged to monitor or control activity at or access to a protected premises.