MDD-1/T

MDD-1/T digital measuring control units are designed to connect one DEX/F, DEX/A, DG/F, DG.EN type threshold detector or one DEX/P, DG/P type measuring detector to the RS-485 industrial standard digital bus with MODBUS RTU protocol.

Features and functions performed

  • assigns three alarm levels to the measuring detector: A1, A2 and A3, set by the user to any value within the full measurement range;
  • assigns two alarm levels A1 and A2 to the threshold detector (according to the detector’s factory settings);
  • allows calculation of the PEL with TWA and average STEL for detectors measuring toxic gas concentrations;
  • allows to determine the type of displayed measurement units of the detector: [%] of the measuring range, [%LEL], [ppm] or [%V/V];
  • enables five modes of operation: “WITH MEMORY” – signals the occurrence of alarms after their disappearance, “UPHOLDING” – sustains active alarm states after the alarm source has disappeared, “A3 MODE” – turns off the power supply to the detector with catalytic sensor, which protects against overload, “WITHOUT MEMORY” – will automatically reset the input and output states on the front panel after the alarm states disappear, “SERVICE” – deactivates unit’s outputs for 1 hour;
  • visually indicates the signal value, the alarm and emergency states of the detector (LED display), the states of the control outputs A1, A2, A3 and the detector’s failure (LEDs);
  • built-in siren;
  • memorizes in a non-volatile internal memory the last 200 events with the assigned start and end times and source of the event;
  • enables very precise determination of alarm delay times and the invariability of these parameters over time thanks to microprocessor control;
  • two 12VDC alarm outputs (one for each A1 and A2 threshold) control additional acoustic and optical sirens;
  • relay outputs (galvanically separated, one for each A1, A2, A3 and failure) control fans, motors, contactors, information boards, or connect to building/plant automation;
  • isolated port in RS-485 standard (MODBUS RTU);
  • in the Digital Gas Detection System (with MDD-256/T type master controller) the connection unit is treated as a “detector”;
  • removable, screwless terminals, possibility of using wires with single or multi-stranded conductors (wires, without crimping sleeves) – quick installation, easy maintenance;
  • mounting on TS35 rail;
  • optional: isolated 4-20mA active analog output (model MDD-1/T/420) or 2-10V (model MDD-1/T/V10) provides control of inverters;
  • configuration of unit’s settings via the dedicated “DETnet View” configuration software, available at https://www.gazex.pl/en/software/.

Offered models

Name Maximum number of detectors Power supply backup Supply voltage Net price C/G
MDD-1/T RS485 TS35 1 24VDC 359.00 zł N
MDD-1/T/420 RS485 TS35 1 24VDC N
MDD-1/T/V10 RS485 TS35 1 24VDC N

Suggested products

Modular switchgear RZ PLUS
Modular switchgear with TS35 rails, equipped and wired according to customer requirements (ready for installation)
GSM modems
Devices designed for remote monitoring of gas detection system status