Bosch has expanded its PRAESENSA IP-based public address and voice alarm system with the launch of the PRA-EOB end-of-branch device, designed to support supervised multi-branch loudspeaker lines in emergency sound system installations. The unit is fully compliant with EN 54-16 and is aimed at projects that use tree or star cabling topologies, which are common in expansion or retrofit scenarios.
The PRA-EOB connects at the end of a loudspeaker line, positioned after the last loudspeaker in a looped series. While it supervises branches, it can also be used to monitor individual loudspeakers. Bosch notes that multi-branch configurations appear in roughly 15 percent of typical PAVA deployments.
Installation flexibility and system integrity
The new device enables individual supervision of each branch on a loudspeaker line, which supports fault detection in installations where cable routes are complex or where infrastructure limits straightforward wiring. According to Bosch, allowing multiple supervised branches on the same speaker line can reduce total cable lengths and shorten installation time in projects where routing efficiency is important.
The PRA-EOB integrates directly into PRAESENSA system supervision. Bosch also reports that the PRAESENSA Open Interface API will offer full support for integrating and monitoring the device.
Addressable pilot tone technology
Instead of impedance measurement, the PRA-EOB uses an addressable smart pilot tone handshake technology that operates over existing speaker cable. Bosch states that this low-energy approach provides advantages such as individual addressing and monitoring of each device on a branched line without setting signal thresholds. This removes the need for calibration during installation.
The pilot tone operates above 25 kHz, making it inaudible to people. Bosch cites this as a benefit for environments where sound sensitivity is a concern, including hospitals, hotels or office spaces. The technology is also designed to remain stable despite changes in ambient temperature.
Availability
The PRA-EOB end-of-branch device is now available. Existing amplifiers require the latest PRAESENSA firmware to ensure full compatibility and functionality.
