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Four Channel Alarm Controller
  • Control system for up to 4 transmitters
  • Graphic LCD shows real-time monitoring
  • Complete calibration functionality
  • Non-volatile memory retains all configuration data
  • Optional discrete channel alarm relays


Bacharach’s GDA-400 controller is designed to provide simultaneous display and alarm functions for up to four fixed-system monitors with 4 to 20 mA inputs. Real-time data displayed on the LCD includes gas type and concentration, bar graphs and 30-minute trends.


The GDA-400 is equipped with a fault and three adjustable alarm levels per channel. Relay outputs allow control of audible and visual alarms, strobes, horns, and other alarm events. Options such as 4 to 20 mA or Modbus® RTU outputs and discrete alarm relays are easily added.



Four channel alarm controller


Four 4 to 20 mA


Backlight graphic LCD, 128 x 64 Pixel; 6 status LEDs


100 to 240 VAC, 24 VDC

Alarm Relays, Common

2 Standard, SPDT

Rating: 5 A @ 30 VDC or 250 VAC, resistive load

Alarm Relays, Discrete

6 optional, SPDT

Rating: 5 A @ 30 VDC or 250 VAC, resistive load

Analog Outputs (Optional)

Four 4 to 20 mA

Serial Port (Optional)

Modbus RTU via RS 485


13 to 122 ºF (-25 to +50 ºC)

Housing Options

NEMA 4X / IP66; NEMA 7 optional


8.0” x 10.0” x 6.25” (210 x 255 x 160 mm)


CE Mark, CSA/UL Div 2 (Pending); NEMA 7: Div 1, Group B