What are 'open' and 'closed' protocols?

'Protocol', in terms of electronic products, refers to the way in which the products communicate with each other and are described as 'open', 'closed', 'digital' and 'analogue'.

In the fire detection industry analogue addressable systems use control panels, detectors and devices such as interfaces which communicate with each other by means of a protocol. Some manufacturers offer both panels and detectors and have no need to disclose the nature of their protocol to anyone, since they offer all the elements needed to provide an analogue addressable system. No equipment supplied by other manufacturers is expected to be compatible with such systems, so the protocol used is said to be 'closed'.

A number of manufacturers of detectors, including Apollo, make no control panels; they have built up partnerships with independent panel manufacturers and other companies. The detector manufacturer determines the protocol used by the detectors and publishes the information and technical data required by panel makers to design compatible panels. Since all details of the protocol must be disclosed, it is referred to as an 'open' protocol.

Apollo has a digital, open protocol.

For a fuller exploration of these issues, please download our Protocols PIN sheet PDF.

Apollo's protocol is available to equipment manufacturers subject to agreement by Apollo Fire Detectors. For details on becoming an Apollo agreed protocol user, please contact our Technical Sales Department.