Data communication over CAN BUS

The GMA300 system is a microprocessor-based, 19” rack mounted gas control system for all measuring functions. Depending on the transmitter type connected, the GMA300 is a complete gas detection system for detection of flammable and toxic hazards, and oxygen.
The GMA300’s highly flexible construction and variety of functions make the system suitable for all gas detection tasks. 3 alarm levels can be set. Additional relay and alarm functions can be configured. All transmitter types can be connected. GMA300 controllers support both 2- and 3-wire devices. The controller supplies power to the attached transmitters, depending on system configuration a large number of measuring points can be connected. In addition to the GMA100 system, the GMA300 offers digital communication via CAN OPEN bus.

GMA300 system versions

GMA301 for 1 transmitter for control of 1 measuring point. 3 alarms and fault output.

GMA304 for 4 transmitters for control of up to 4 measuring points. 3 common alarms and fault output.

Simple operation
Gas concentration is continuously shown on a 3-digit LED display. Gas concentration, gas type and detection range can all be displayed via a simple button push. Zero and span adjustment can also be performed simply via the simple operation from push buttons. The controller has a min/max memory that enables the user to check the exact concentrations encountered after a gas alarm has occurred. In addition, the highest or lowest measured value is stored and displayed in the LED display. A 4-20mA output (GMA 301) is available to transmit gas measurement readings to external devices.

Alarm functions
3 alarm thresholds can be set. Additional relay and alarm functions are adjustable: exceeding/falling below, latching/not latching, quiescent current/full load current, open/normally closed contact, signal delay and hysteresis. 4 LED lights display operation status, alarm and fault signals.

Delta alarm
The delta alarm function can be used to ensure the fastest response to a gas leak. Not only the measured gas concentration is considered, but also the rate of rise of the measured value. An unusually fast rate of rise can be used to trigger the alarms, even before the normal threshold value has been reached.

The advantages at a glance

• Simple rack mounting
• Measured values and alarms are displayed on each channel
• Digital interface CAN OPEN bus
• Simple operation
• Menu-led service operation
• 4 relays for 3 alarms, 1 fault alarm