Relay module for extension of the GMA200 series and the GMA22

The relay module GMA200-RT extends a controller of the GMA200 series or the compactly designed GMA22 in a gas detection system by 16 individually programmable relays with one potential-free change-over contact each. This allows additional safety measures such as visual and audible alarms or ventilation systems to be operated via the controller. The relay module GMA200-RT has LED indicators and is connected to a controller via the RS-485 interface. It can be mounted on a top-hat rail (TS35), in a control cabinet or in a wall-mounted housing GMA200-RTW.

GfG controllers and certain transmitters have internal relays. External alarm devices such as information signs, warning lights and signal horns can thus be directly connected and managed. The same applies to measurement-controlled ventilation systems and valves. Complex gas warning systems, however, require a large number of automatic safety measures that are initiated when the defined gas limit values are exceeded or undershot. Up to four relay modules GMA200-RT can be connected to the GfG controllers via the RS-485 interface. The total number of relays per gas detection computer can thus be increased by up to 64.

Extension of safety functions
The GMA200-RT is equipped with 16 relays, each with a potential-free changeover contact. In addition to 16 external alarm devices or other measurement-controlled devices and functions, an external pushbutton can also be connected for alarm acknowledgement. Due to the spatial separation of controller and relay module, safety measures in remote areas (up to 1,200 m) can be implemented with significantly less cabling effort. The operating voltage of the GMA200-RT is 24 V DC. Power supply is also possible redundantly via two power supplies. The device is configured via a gas measuring computer (using GMA200Config software) or via the mini-USB socket (USB type B) using a PC.

Indicators and Functional Safety
For each relay, an LED on the front of the relay module lights up to indicate operation and any alarms or faults in color. In addition, four status LEDs indicate the operating status as well as service and error messages. The hardware of the GMA200-RT meets the requirements of functional safety according to DIN EN 50402. In single-channel use (1oo1), the SIL capability corresponds to 2, in redundant use (1oo2) to 3.


Key features at a glance:

Generall information:

  • Suitable for the GMA200 and GMA22 gas detection computers
  • 16 relays with one potential-free change-over contact each with status display
  • Connection via RS-485 interface (Modbus)
  • Connection of up to 4 relay modules per controller
  • Top-hat rail mounting (TS35)
  • Configuration via software GMA200Config with gas measuring computer and PC

Optionally available:

  • SIL level 2/3 (depending on contact load of relay switching output)


Extensions and accessories



Relay module for wall mounting to expand the GfG controllers
» more

Accessories GMA200-RT

Accessories GMA200-RT

Complete list of accessories for the GMA200-RT
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