Three decades ago, the protocol debate in building automation systems (BAS) did not exist. Every element of a BAS, from the sensors to the control devices and wiring, were installed around a single product from a single manufacturer. Building owners were locked into a system and each replacement part had to come from the original equipment manufacturer. Changing the BAS was no mean feat either, and involved altering everything from the control panel and front end, to the network and setup.
Fast forward a few years to the introduction of options such as BACnet, and the protocol floodgates have opened. Building services engineers have become used to BAS that bring a new level of choice, efficiency and functionality in today’s buildings. The systems have become far more cost effective and can be selected and tailored towards each unique application.
In the fire industry, the open versus closed protocol debate goes back several years, and is probably one of the longest running topics. Everyone has an opinion, and discussions are often fuelled by the fire detection experts’ differing interpretations of what defines open and closed protocol. The definition is certainly not clear cut, and the confusion has grown, alongside the increasing number of fire detection and alarm (FDA) products available on the market.
The main problem in the FDA systems industry is that there is no textbook definition covering the different protocol options. Not everybody fully understands what the terms really mean and many views are often based on individual preferences towards a particular manufacturer’s products. In order to understand all sides of the argument, we need to look closer at the workings of an FDA system.
In analogue addressable fire systems, there are three main protocols that are used when individual elements are wired together to build a system. First, there is the loop protocol which enables all of the detectors, call points, sounders and interfaces to communicate with a panel. Then there is the network protocol which enables all of the panels to communicate with each other. Finally, there is the supervisory protocol that allows external monitoring, reporting and control from a building management system or head-end monitoring package.
Out of these three, it is only the last one that is currently available as a true open protocol as the protocol is publicly available and free for anyone to use. All fire panel network protocols are actually closed, since they are manufacturer specific. Panels from manufacturer A will not communicate with manufacturer B. So, once a decision has been made to install a network of panels from a given manufacturer; all additions will also have to be from that company and may even need to be from the same product family, if the manufacturer has several incompatible ranges.
In terms of fire loop protocols, these are also closed as once a device is installed, you cannot mix another manufacturer’s device on the same loop. Once a decision has been made to use detectors from a given manufacturer, all future loop devices need to be supplied from the same company.
It is almost always the loop protocol that is being referred to when the term open or closed protocol is used for a fire system. On this basis, true open protocol systems do not actually exist in our industry. If they did, users would be able to mix and match detectors from different manufacturers on a loop or mix panels from different manufacturers on a single network. In practice, all loop and network protocols are specific to a particular device manufacturer.
In the FDA industry, when the phrase ‘open protocol’ is used, what people ultimately mean is that they want choice – the ability to choose where to buy the system and who can commission and maintain it. The same as the wider BAS, customers do not want to be locked into a single provider for the lifetime support of their system. The issue is really not about protocols at all. The key question is: Does the manufacturer make commissioning tools, training and parts available to allow multiple third parties to commission and maintain the system? If yes, the system is open, if no, the system is closed.
This is a much simpler and more accurate way to assess whether the system will give people what they are expecting when they ask for open or closed. However, as straightforward as this seems, again there are a few exceptions. Some manufacturers who offer closed systems allow restricted access to training and maintenance tools for a number of their products. In effect, it is the product ranges, rather than manufacturers, that need to be categorised as open or closed.
In addition, some open systems are almost completely unrestricted in the availability of parts, tools and support. Others are only available through a set of factory approved and trained distributors. Both of these offer choice and competition, with a trade-off between total freedom of choice and the assurance of always getting a factory supported and trained supplier.
Which is best out of these options in any given application is not easy to answer since each has advantages and disadvantages, and, in light of today’s cost cutting pressures, they all have differing financial implications.
Closed protocol effectively means that one company is responsible for the entire system. From the manufacturing and supply process, to the installation, maintenance and upgrades, one single company has sole ownership of the software tool – a similar scenario to the pre BACnet BAS. The biggest benefit of a closed FDA system is that the customer is essentially buying the expertise of one company. A single point of contact brings simplicity and the added security of knowing the expert engineers will be fully trained and experienced in each specialist area.
The major disadvantage of a closed system is the lack of choice. There is complete dependency on one company for spare parts, modification, upgrades and access to the protocol for servicing. It is also commonly perceived to be the more expensive option as the inability to shop around can put a premium on on-going maintenance.
What are termed as open systems allow customers access to a wider market. Generally, various companies can manufacture the different components, such as control panels and detectors, and anyone can buy the equipment and have access to the software tool. Freedom of choice is the obvious benefit for customers, however, as anyone can work on the system, there is no guarantee that an engineer has the required expertise or has received full training on a product.
At Gent, our systems are as open as any other fire company as we offer customers choice in purchase, installation, commissioning and on-going service and maintenance. Anyone can maintain our systems, as all routine actions can be accessed from the front of the panel.
The Regulatory Reform Order states that it is the responsibility of the building owner/occupier to ensure that competent people are employed to install, commission and maintain their fire system. We have a network of approved Systems Integrators, who provide end user customers with the required competitive choice in the market place. The engineers in these specialist companies are BAFE or LPS1014 and are fully trained on the product before the software is issued. This ensures that customers have an expert provider on site, as well as the choice of alternative service providers if required.
The protocol debate may be complex and confusing but ultimately the decision of which system to choose needs careful consideration, taking into account quality and reliability as
well as cost and long term support. Part of this decision may be based on whether the system is open or closed, but this has little to do with protocols, it is more about choice, the most important value for every customer.