The SMC Model 4001 Controller is a comprehensive hazardous gas detection monitoring system designed with flexibility and features to meet specific light industrial applications, such as wastewater. Its user-friendly design makes installation and operation a simple task. View Datasheet: The controller operator interface and menu navigation can be accessed on the controller using a simple rotary push button to select and enter parameters on a brightly illuminated color LCD. The display changes color depending on alarm state: Green is normal, Yellow is Warning, Red is Alarm, and Blue is Fault. The three relays are Form C SPDT, rated at 5 Amps to connect to notification systems and appliances. The relay action can be selected as Non-Latching or Latching with a remote acknowledge input. Modbus RTU output is provided for connection to various supervisory systems, or an optional gateway. The analog output is a 2-wire retransmission of the measured input for trending or recording. Features & Benefits: