The 9010 (single channel) and 9020 (dual channel) controllers are gas-warning systems that can monitor up to 20 channels at once. Each module features an an independent AC/DC power supply for increased system reliability and full internal diagnostics to minimize false alarms. The controllers can also power remote sensors, while the large four-digit LCD and LED provide such crucial information as gas concentration and alarm status. A convenient RS-485 serial interface offers a printer connection for data collection and the Modbus RTU can record serial bus data transmission.