Device group: Threshold control units
Device type: MD-1, MD-2, MD-4

MD-1, MD-2 and MD-4 dual-threshold alarm modules are designed to control and supply 1/2/4 of the DEX/F, DEX/A, DG/F or DG.EN type threshold gas detectors for use in the Dual Threshold Gas Detection System and Active Gas Safety System GX (ASBIG®).

The alarm module can control from one up to four detectors. The module can control additional external optical and acoustic signaling devices and enables communication with other devices via relay outputs (or an RS-485 port for MD-1…).

Modules with shut-off valve control output version can control a gas shut-off valve. Such module is a component of „the signalling and shut-off system” according to the requirements of the Regulation of the Minister of Infrastructure of the Republic of Poland dated April 12, 2002 on technical conditions to be met by buildings and their location (Journal of Laws 2002 No. 75 + changes).


  • power supply for dual-threshold detectors (with load control and wired connection);
  • optical indication and memory of the detector’s alarm states and control outputs;
  • Alarm input (for A2, galvanically separated) for fire systems or manual valve switch;
  • 12VDC alarm outputs – supply of additional acoustic and optical signalling devices;
  • relay outputs (galvanically separated) - control of fans, contactors, information boards;
  • relay output „FAULT” (galvanically separated) - informs about emergency state of the module or power failure;
  • power supply of additional module for remote control of valves;
  • for MD…Z: high-current output 12VDC to control a MAG-3 type shut-off valve (with connection control);
  • automatic power supply backup (for MD-1.Z version);
  • in /M version: RS-485 port for connection to the Digital Gas Detection System or for configuration/reading of event memory data to PCs via dedicated configuration software „DETnet View”, available at

Block diagram

Device model: MD-4.A24

Technical parameters

Maximum number of detectors
Alarm control outputs 12VDC
Contact control outputs
Emergency control output
Alarm inputs
Supply voltage
240 x 215 x 115 mm
EAN Code
Net price
PLN569.00 N


Series Technical data Device information sheet Instruction manual Declaration of conformity
U4 Download file
U3, U3p Download file Download file Download file

Suggested products

Service batteries AKU-07GX
Batteries designed to generate a control pulse for the shut-off valve in MD-...Z type control units
Modems GSM
Devices designed for remote monitoring of gas detection system status
Installation switches SW-20
Double switches for 230 AC power supply