The Modbus converter BSL-330 is an RS232/422/485 interface converter used to interface various PLC equipment (Programmable Logic Controllers) to the AutroSafe interactive fire detection system. The converter is both a physical and a logic protocol converter. At the physical connection level, it transforms an RS232 connection to an RS485 or RS422 connection. This is convenient as this type of connection is safer in noisy environments. RS232 is available as an option.

The converter is connected to the AutroSafe via the AutroCom protocol. It communicates with both protocols by means of the conversion software. A master Modbus device polls the BSL-330 converter for reading its registers. It expects a response within a defined time period. Communication can be over various serial mediums. The one used here is the Modbus RTU protocol over an RS485 link (RS232).

The BSL-330 is available in four versions:

• BSL-330/1: AutroSafe Modbus converter slave RS485
• BSL-330/2: AutroSafe Modbus converter master RS485
• BSL-330/3: AutroSafe Modbus converter slave RS232
• BSL-330/4: AutroSafe Modbus converter master RS232