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-RTD 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-RTD is equipped with 16 relays, each with a floating signal 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-RTD is 24 V DC. Power supply is also possible redundantly via two power supplies. The device is configured via a gas measuring computer (by GMA200Config software) or via the mini-USB socket (USB type B) by PC.
Displays and Functional Safety
The GMA200-RTD displays the measured values of the transmitters connected via the controller as individual or collective values. In the event of an alarm, the background of the 2.2-inch color display will change to red. The relay module is operated via a push button interface next to the display. Each relay is represented by an LED on the front of the relay module, which will change color to indicate its operation as well as any alarms or faults. In addition, four status LEDs notify you of the operating status and any service and error messages. The hardware of the GMA200-RTD 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:
- Suitable for GMA200 and GMA22 controllers
- 16 relays, each with one potential-free changeover contact with status display
- 2.2 inch color display and push button interface
- Connection via RS-485 interface (Modbus)
- Up to 4 relay modules per controller
- DIN rail mounting (TS35)
- Configuration via GMA200Config software, controller and PC
Approvals / Certifications:
- SIL level 2/3 (depending on contact load of relay switching output)