Building drivers for proprietary protocols can be expensive, and since each one is unique, it can only be used with the system for which it was developed. On the other hand, since proprietary drivers are developed for a specific system, they tend to be perfectly suited for use with that system and provide the full range of functionality available.
"Another benefit," said Tom Rule, product manager for Siemens Building Technologies (Buffalo Grove, IL), "is that most fire and life safety systems have proprietary protocols built into the panels. This means that external third-party devices are not required to translate information from the life safety system to the BAS."
Open protocols can be advantageous, because once they are developed, they can be used over and over for integrating multiple systems. Being able to reuse drivers offers significant cost saving to manufacturers who would otherwise have to build individual drivers for each system. However, there are some disadvantages as well.
For example, standard protocols sometimes don't support the unique functionality available with a particular system. Another problem is that manufacturers typically don't support the entire standard protocol. Manufacturers may select the parts of a protocol that are relevant to their systems, or sometimes support only a bare minimum of functionality, so they can claim to support the open protocol. In these situations, only a small amount of information or interoperability might be available.
Another concern with open protocols is that many vendors rely on third-party devices to translate their proprietary protocol to an open standard, which adds another level of complexity to commissioning and maintaining these interfaces.
Rick Focke, director of marketing for Tour Andover Controls (Andover, MA), noted that while proprietary fire alarm protocols are still very common today with each BAS manufacturer having to develop a unique software interface for every life safety system, standard protocols are beginning to have an impact. "BACnet introduced life safety objects and services in addendum C to the 2001 standard, and these changes are now rolled into the 2004 standard. There are also numerous OPC, LON, and Modbus implementations of fire/life safety functions. In fact, there are two BAS manufacturers that have received UL listings for smoke management based on the BACnet open standard."
An emerging trend is the use of a customer's Ethernet infrastructure to transmit data between systems. Although this can be an efficient use of existing resources, there are definitely questions about the reliability of the network and agency listings.
"Typical building networking devices (hubs, switches, and routers) are rarely listed for use with a fire alarm system and often don't have the secondary backup power required to ensure that the fire alarm system will continue to function during a power failure. To ensure reliability, separate sub-networks, dedicated for the fire alarm system are often required," Rule said.
BenefitsEven taking into consideration cost and protocol issues, there are numerous benefits to integrating life safety and BAS. The most obvious benefit is providing interoperability between systems. As Rule noted, "When the life safety systems and BAS can communicate, inputs on one system can trigger reactions on another."
An example of this is a smoke control application, where the BAS controls the air-handling systems and can efficiently manage fan and damper systems based on inputs from the fire alarm system. Other applications include activation of lighting for safe egress, or using the automation system to trigger CCTV events that allow remote operators to view and capture live video data from an area of incident.
As Focke noted, "Integration allows a coordinated response. A fire alarm can trigger specific lighting zones on, doors open, fans off, elevators recalled, and start a muster report process to account for all employees in the building." He added that integration also provides quicker, system-wide alarm annunciation, even through pager, cell phone, and e-mail.
Basically, an integrated system allows information to become more readily available. Data in a fire alarm system is typically accessed through a small LCD screen or a printer, while BAS typically include a workstation running on a PC. When the life safety and automation systems are integrated, operators can view data from both systems through the same workstation interface. Additionally, a workstation provides superior long-term data storage, formatting, and reporting capabilities, not typically available through a field panel interface.
Another benefit to integration is that it leverages the BAS capabilities. It is common for automation systems today to provide Internet access and advanced remote notification of system events through technologies like paging and e-mail. "Any systems that are integrated to the BAS can share these same capabilities, so when the life safety system is integrated, users get instant access to any Internet and remote notification capabilities of the automation system," Rule said.
Reduced or shared costs are another reason why endusers are anxious to integrate their systems. At facilities where both life safety and automation workstations are required, integration provides an opportunity to meet the needs of both with a single platform. Even when multiple physical workstations are required, a good deal of rework can be eliminated. For example, custom floor plan graphics can be re-used, service upgrades can be done all at once, and system backups for both systems can be done together.
Integrating life safety and automation systems also allows endusers to leverage their personnel investments. "Hopefully, most of the activity on a building's life safety system will be for testing, maintenance, and non-emergency trouble or supervisor type conditions. Since the facilities maintenance group that is already using the BAS for other building functions generally manages these types of situations, it is advantageous for those operators to have direct access to the life safety system through that same interface," said Rule.
Additionally, security staff can often be used to assist in monitoring building automation functions during evening and weekend hours when maintenance people aren't on-site. "Bringing life safety and automation data into a common interface makes interaction with the systems easier for the people using these systems, because there is only one interface to learn, and everyone is using the same interface," Rule said.
However, the situation can get a little sticky when the people responsible for life safety and automation are completely different entities with separate budgets and reporting structures. In these situations, individual groups may not be motivated to share resources or give up complete control of the interface to their system.
Chances are that in the near future, though, these different entities may not have a choice as to whether or not their life safety and BAS are integrated. That's because fire and life safety systems are the systems most frequently integrated with the automation system. And it's probably not a coincidence that life safety objects were the first added to the BACnet specification after it was initially introduced for automation communications. ES
University of Connecticut Benefits From IntegrationThe University of Connecticut (UCONN) recently experienced the benefits of integrating its BAS and smoke management systems. The university chose Andover Controls to provide centralized HVAC control for 53 of its academic and utility buildings, residential halls, and sports facilities on its main Storrs campus, as well as several satellite locations in Connecticut.
The first Andover project funded under Phase II was the new Chemistry Building. This new 208,309-sq-ft, five-story building is the first of several buildings in UCONN's new "Technology Quad" envisioned to centralize the science and engineering programs on campus. The building was designed with state-of-the-art ventilation features in both the teaching and research areas. Because of the environmentally sensitive use of chemicals in this facility, the regulation of airflow and HVAC system control is critical.
In this critical environment, all lab parameters are monitored precisely, including hood sash positions and process chilled water usage. If lab occupants leave their hoods open or dump process chilled water down the drain, UCONN's facilities personnel will know and take action.
The building was also designed to be energy efficient. A glycol preheat/pre-cool loop used for heat recovery in winter and pre-cooling in summer, advanced fume hood control, daylight dimming systems, and energy-efficient lighting are just some of the many energy saving features controlled and/or monitored by the Andover system.
A total of 3,456 input/output points were installed for HVAC control, lighting control, and laboratory control and monitoring. In addition, an Andover Controls "XDriver" software interface provides communication between the Andover system and the building's fire alarm system.
A four-story atrium in the building utilizes Andover's smoke management capabilities. This part of the system, certified to UL 864, UUKL smoke control standards, controls several large supply fans that deliver 128,000 cfm, and exhaust fans that remove 150,000 cfm from the atrium area.
"This application shows how you can easily add smoke management to an overall campus-wide BAS, and not have to install a costly standalone smoke management system," said Focke.