The GDS Corp. C2 Two Channel Display / Alarm Controller is designed to provide simultaneous display and alarm functions for two gas detection variables. A graphic LCD displays monitored data as bar graphs and engineering units. Three adjustable alarm levels are provided per channel. Relay outputs allow control of beacons, horns and other alarm events.

The C2 Protector controller supports industry standard 4-20mA inputs as well as direct connection to electrochemical sensors for toxic gases, catalytic bead or SmartIR infrared sensors for combustible gases or photoionization (PID) sensors for Benzene or other volatile organic compounds (VOCs). Combustible or PID sensors may be remote mounted. When using the direct sensor input option, any combination of toxic and/or combustible may be configured.

The C2 is easy to configure and user friendly. Measurement ranges in engineering units, adjustable alarm set-points, optional serial interfaces, and many other features offer flexibility to meet most demanding applications.

An optional RS-485 Modbus slave port allows up to 128 C2’s to be multidropped onto a single data highway for interrogation by a remote MODBUS master device. A MODBUS TCP interface is also available for ethernet network applications.

Available C2 options include 5 amp SPDT discrete alarm relays per channel, 4-20mA outputs, light stacks and audible annunciators.

Brochure Manual


  • Analog input, direct electrochemical sensor input for toxics/O2 or direct bridge-type sensor input for combustibles/VOC
  • High resolution LCD with graphic display and channel-specific indicator LEDs for quick problem identification
  • Alarm LEDs flash when new and become steady when acknowledged
  • Channel-specific display with short term trend data
  • Three independent alarm levels per channel that include setpoint, on/off delay, alarm above / below and voting options
  • Built-in calibration mode offers pushbutton zero / span calibration for direct sensor interface applications
  • Standard outputs include two programmable common relays plus MODBUS slave interface
  • Optional discrete channel-specific relays and 4-20mA outputs
  • Magnetic keypad available for nonintrusive operation in potentially hazardous locations
  • CSA approved for Class I Div 2 areas without purge. CE mark
  • NEMA 4X and NEMA 7 Explosion-Proof packaging options available
  • Authorization Mode allows locking of critical configuration variables