GfG 1-4 Channel Controller

The GfG GMA22-M controller is a versatile, multi-channel control unit designed to manage and monitor fixed gas detection transmitters across a wide range of applications.

Capable of connecting up to four gas transmitters, the GMA22-M acts as the central interface between field sensors and building control systems—providing real-time data, alarm handling, and system control in one compact device.

Centralised Control for Safer Systems
Rather than relying on standalone detectors, the GMA22-M enables centralised monitoring outside hazardous areas, improving safety and accessibility.

• View all gas readings in one location
• Acknowledge alarms without entering risk areas
• Install at entrances, control rooms, or plant areas

This approach enhances both operator safety and system usability.

Designed to Control Multiple Transmitters

The GMA22-M is purpose-built to work with a wide range of GfG transmitters, including:

• CO / NO₂ car park sensors (EC22 / EC22DS)
• CO₂ and IR sensors (IR22D)
• Toxic, refrigerant, and combustible gas transmitters

It supports:

• Up to 4 measuring points (transmitters)
• Monitoring of toxic gases, combustible gases, and oxygen

This makes it ideal for small to medium systems such as:

• Car parks and tunnels
• HVAC plant rooms
• Refrigeration systems
• Boiler and mechanical rooms
• Flexible Connectivity & Integration

The GMA22-M offers flexible integration options to suit both new builds and retrofits:

• RS-485 (Modbus) for digital communication
• 4–20 mA / 0.2–1 mA analog inputs for universal compatibility
• Compatible with BMS, PLC, and SCADA systems

It can also receive status and service information from connected transmitters, improving diagnostics and maintenance planning.

Built-In Alarms & Control Outputs
Safety is built into the controller with:

• 4 integrated relays for triggering ventilation, shutdowns, or alarms
• Expandable up to 64 relay outputs using additional modules
• Integrated audible alarm (horn)
• Visual alarm indication via LEDs and display

This allows direct control of:

• Ventilation fans (car parks, plant rooms)
• Alarm systems
• Safety shutdown processes

Clear Display & User-Friendly Operation

• 2.2” colour display with real-time gas readings
• Colour backlight (green = normal, red = alarm)
• LED indicators for alarm, fault, and status
• Simple push-button interface for operation and alarm acknowledgement

Operators can quickly assess system status at a glance and respond immediately.

Compact, Robust & Easy to Install

• Compact wall-mounted design (fits almost anywhere)
• IP64-rated enclosure for dust and splash protection
• Suitable for plant rooms, control rooms, and service areas
• Optional data logging via microSD card for compliance and reporting

Key Features

• Controls up to 4 gas transmitters
• Centralised monitoring of toxic, combustible gases and oxygen
• BMS/PLC integration: Modbus RS-485 and analog inputs
• 4 onboard relays, expandable up to 64
• Integrated visual and audible alarms
• Colour display with real-time readings and status
• Compact IP64 enclosure for flexible installation
• Optional data logging for compliance and analysis

Typical Applications

• Car Park Ventilation Systems
• Control of CO / NO₂ sensors (EC22 / EC22DS)
• Demand-controlled ventilation (DCV)

Building Services

• HVAC plant rooms and mechanical spaces
• Boiler rooms and energy centres

Refrigeration & Industrial

• Cold storage and refrigeration plant
• Light industrial and utility systems