Bosch PRA-SCL System Controller Audio Routing Devices, Large

The Bosch PRA-SCL is the most powerful version in a range of system controllers. The Bosch PRA-SCL system controller manages all system-related functions in a PRAESENSA Public Address and Voice Alarm system. It routes all audio connections between network-connected PRAESENSA audio sources and destinations. It supervises and plays back messages and tones, stored on its flash memory, either scheduled or manually started from a call station or PC. It manages the routing of background music streams, along with business calls and emergency calls, all based on priority level and zone occupancy.

It collects all status information of connected system devices, manages the event logs, and reports faults. The system controller is network‑connected via OMNEO and DC‑powered from a multifunction power supply with integrated battery backup, accommodating both centralized and decentralized system topologies. Connections to other devices in the system are made using the built‑in 5‑port switch, supporting RSTP. The built‑in web server allows for system configuration using a browser.

System Control and Audio Routing

• Capability to control a system with up to 250 devices, serving more than 500 zones.
• Native support for switched single‑subnet networks, with add‑on support for routed multi‑subnet topologies.*
• Dynamic allocation of multiple and simultaneous audio channels to save on network bandwidth; audio connections are created when a call or a message is broadcast and freed up immediately afterward.
• Secure interconnections using Advanced Encryption Standard (AES128) for audio data and Transport Layer Security (TLS) for control data.
• Receiver for Dante or AES67 audio channels from external sources, with dynamic re‑routing to open or secure OMNEO channels.
• Internal storage capacity for messages and tones; up to eight messages can be played back simultaneously.
• Internal real-time clock for scheduled events and event time-stamping; support for Network Time Protocol (NTP) with automatic adjustment for Daylight Saving Time (DST).
• Internal system event and fault event log.
• Networked control interface for third-party applications.
• Built‑in web server for configuration and file management using a browser.