Is interfacing between fire detection and BMS permitted in Belgium?
Yes, interfacing is permitted and is increasingly requested in tertiary and industrial sites equipped with a building management system (BMS, or GTB). The fire detection panel can transmit its information to a BMS supervisor to centralise alarms on a single screen. The limitation concerns the nature of the exchange: the Belgian standard NBN S 21-100-1, which governs the design and installation of fire detection systems, requires that the panel remains autonomous equipment for its safety function. The BMS can receive information; it cannot become a necessary link in the operation of fire detection.
What information can the fire alarm panel transmit to the BMS?
The fire alarm panel can transmit to the BMS the fire alarm status, fault status, the deactivation of a zone or detector, and the time-stamping of events. This transfer is generally done via volt-free contacts (dedicated relays at the panel output) or via an open communication protocol such as Modbus, BACnet or OPC through a gateway.
This information feeds a BMS dashboard allowing technical staff to visualise at a glance the status of several buildings or several zones of the same site. History export also facilitates the traceability required during periodic inspections according to NBN S 21-100-2. This direction of flow (from the panel to the BMS) is what the standards admit without reservation, because it introduces no dependency of safety on a third-party system.
Why does the standard impose a separation of safety functions?
The standard imposes a separation of safety functions because fire detection must continue to operate even if all other technical systems in the building fail, are updated or are shut down. A BMS is a management IT system (heating, ventilation, lighting) whose availability is not guaranteed at the same level as a safety installation.
The fire alarm panel has an autonomous backup power supply, continuous self-monitoring of its circuits and detectors, and BOSEC certification of its components. None of this is required of a standard BMS. If the safety function depended, even partially, on the proper functioning of the BMS, a common IT failure could compromise fire detection. This is the risk that the autonomy principle of the Royal Decree of 7 July 1994 and NBN S 21-100-1 aims to prevent.
Can the BMS control safety actions such as smoke extraction?
No, the BMS cannot control fire safety functions such as smoke extraction, triggering of the general alarm or closing of fire doors. These commands remain the exclusive responsibility of the fire alarm panel's control equipment, which applies positive and tested safety logic.
One exception exists: an interface can transmit a command to the BMS (for example, shutting down ventilation in case of alarm), but never the reverse for a safety function. If cross-control is envisaged, the interface itself must be designed, powered and monitored according to the same requirements as the panel, which in practice amounts to integrating it into the certified perimeter rather than treating it as a simple BMS accessory.
What functions can pass through the BMS without risk to safety?
| Function | Permitted direction | Compatible with BMS |
|---|---|---|
| Display of alarm/fault status | Panel to BMS | Yes |
| History and event export | Panel to BMS | Yes |
| Mapping of zones in alarm | Panel to BMS | Yes |
| Triggering of general alarm | None from BMS | No |
| Smoke extraction control | None from BMS | No |
| Deactivation of a detector | Reserved for panel | No |
| Ventilation shutdown in case of alarm | Panel to BMS (command) | Yes, downstream |
This table summarises the general principle: the BMS consults and displays, it never decides in place of the panel for a safety function.
How to verify that interfacing remains compliant over time?
Interfacing must be verified at each periodic inspection of the installation, carried out according to NBN S 21-100-2 by a qualified technician. This inspection verifies that the panel maintains its operational autonomy (backup power supply, self-monitoring) independently of the BMS status, and that connections to the BMS have not been modified to introduce a command.
The installation's technical file must precisely document the nature of the interface (protocol, flow directions, contact points) so that the emergency zone (hulpverleningszone) or the prevention adviser can assess the setup during their opinion. Any modification of the BMS by the building's IT department, even without apparent connection to safety, must be reported to the fire detection installer to verify that it does not affect existing interfacing points.