MDP-8/M

Measuring alarm modules type MDP are designed to control and supply power to gas detectors of the type DEX/F, DEX/P, DEX/A, DG/F, DG/P and DG.EN for use in Two-Way (or Measuring) Gas Detection System or in Active Gas System Safety GX (ASBIG^®).

Modules can control from one to four (MDP-4…) or up to eight (MDP-8…) or up to sixteen (MDP-16…) detectors.

Modules can control additional external optical and acoustic signaling devices and enable control and cooperation with other devices through contact outputs and standard RS485 digital port. They can cooperate with other modules or systems via opto-isolated inputs. MDP…Z… can control shut-off valves.

Features

• compatibility with GAZEX measuring gas detectors with standard 4-20mA passive output types DEX/P, DG/P;
• possibility to work with GAZEX threshold detectors types DEX/F, DEX/A, DG/F, DG.EN (with K-8P and K-16P cable hub box);
• control of the current consumed by individual detectors – in case of failure of any of them – automatic disconnection of power supply (does not block operation of the remaining, independent hardware and software protection);
• control of wired connection with the detectors (ensures full detection of emergency states, specifying the type and place of failure);
• assigning three alarm levels to the measuring detector: two user-adjustable to any value within the full measuring range (A1 ≤ A2 ≤ 100% of the range); the third fixed - A3 determines when the measuring range of the detector is exceeded;
• assignment of two alarm levels A1 and A2 to the threshold detector;
• calculation of PEL with TWA and STEL for toxic gas detectors;
• possibility to determine the type of displayed measurement units of the detector: [%] of the measuring range, [%LEL], [mA] or [ppm];
• possibility of assigning individual detectors to one of two zones, enabling control of different external devices depending on which group of detectors the alarm condition occurred (in effect creating two detection systems);
• MDP-…Z… controls the operation of two shut-off valves and controls the state of the module’s line connection with valves (one valve assigned to one zone);
• three additional operating modes are possible: „SILENT WORK” – silences the internal piezoceramic siren permanently or temporarily (for 15 minutes) blocks the siren at output A2 (12VDC); „SERVICE MODE” - temporarily deactivates the module outputs; „AUTO RESET” - will automatically reset the input and output memory states on the module display after the alarm states disappear;
• possibility to close the valves by manually triggering the output control signals (without the need to generate the detector alarm signals);
• indication of alarm and emergency states by displaying appropriate messages on the LCD graphic display and switching on LED lights, with simultaneous acoustic signalling (built-in siren);
• possibility to choose the type of displayed messages on the LCD screen between the „measurement” view containing current values of the detector signals scaled in specific measurement units and the „threshold” view containing messages about set alarm and emergency I/O states of the module;
• non-volatile internal memory of 1600 last events with assigned start and end time and source of the event;
• possibility of precise determination of alarm delay times;
• possibility to activate outputs depending on the number of alarms at the inputs: at least 1 or 2 detectors in alarm state;
• four relay outputs (galvanically separated from the system) for control of fans, motors, contactors, information boards, or to connect to building/plant automation;
• two sets of 12VDC alarm outputs – to control additional acoustic and optical alarm devices (2 outputs for each zone);
• the „FAULT” contact output (galvanically separated from the system) informs about the module’s failure status, fuse damage, damage to the connection line with the detector or power failure;
• two alarm inputs (galvanically separated) for cooperation with additional devices and modules (cascaded);
• possibility of supplying 12VDC external devices, e.g. additional MD-X.ZWA modules or manual valve closing switches;
• all removable, self-tightening connectors, with the possibility of connecting wires with single or multi-stranded conductors (wire, no crimping of sleeves) = quick assembly/start-up of the system and easy maintenance/replacement;
• standard serial communication port RS-485 enables cooperation with control systems of „intelligent building” (according to MODBUS RTU protocol) or visualization of device status on PC screen using „MD16 View” software - available at https://www.gazex.com/en/software/.

Block diagram