MX 43

MX 43 is a Flexible, High Quality, Easy to Use Gas Detector

Fully scalable, the MX 43 is an analog and digital controller designed to continuously measure and control gases in the atmosphere. The MX 43 manages both digital lines and analog channels, and covers all needs for a wide variety of applications. The MX 43 digital technology allows up to 32 detectors to be distributed on 8 lines for increased cost savings.

USB Module for Improved Storage Capacity

Oldham has improved the storage capacity of its MX 43 controller by adding an USB module. The USB option provides the user the following benefits:

  • continuous data logging on the USB key at a user defined sampling rate from 2 seconds to 15 minutes,
  • recording in real-time of all events (alarms, faults, alarm resets, calibration etc.)
  • automatic backup of the configuration
  • automatic backup of the firmware
  • loading a configuration or a firmware file from the USB stick in order to restore or update the system easily.

The 4GB USB drive fitted with the USB kit, provides a recording capacity of more than 2 years (18 months in the worst case for a controller equipped with 32 detectors), a 2 second sampling rate (32 measurements every 2 seconds), and 100 events per day per detector (3200 events per day).

The COM 43 Programming CD

The MX 43 is now available with a programming CD that is compatible with any MX 43 controllers already in use. The COM 43 is a simple application that gives user access to the advanced features of the MX 43 controller and makes programming fast and easy to do on one's own. Users save precious time by configuring the controller's parameters on their computer and transferring these parameters directly to the MX 43 using a USB cable.

Programming is quick and easy: the COM 43 application can be installed on a computer from a CD and gives access to all of the controller's options:

  • Configuration of measurement channels
  • Simplified relay programming
  • Up to 5 on-board functions: OR, AND, NOR, NAND, VOTING
  • Advanced management of audible alarms with timer options (holding time, automatic acknowledgment, reactivation, evacuation)

COM 43 is equipped with useful features that make programming easy, quick, and secure:

  • Graphic display for easy relay programming
  • Architecture displayed progressively as the programming process is completed
  • Access to an Oldham gas monitor library pre-programmed according to industry standards
  • Highly practical "copy-paste" function saves time by preventing programming errors from one sensor to the next
  • "Verification/validation" feature to ensure correct programming and to flag any programming errors before validating
  • Transfer settings to the controller in just a few seconds


The CD also contains the French and English user manuals for the COM 43 and the MX 43 controller.



MX 43 gas detection control panel

(wall-mounted version):

370 x 299 x 109 mm (14.6 x 11.8 x 4.3 inches)

Dimensions (rack):

19", 4U ; 482.8 x 177 x 192.5 mm (19.1 x 7 x 7.6 inches)

Ingress protection:

IP55 (wall-mounted), IP31 (rack)

Cable entries
(wall-mounted version):

12 M16 cable glands, 4 to 8 mm2 (8 to 11 AWG) outer diameter cable
6 M20 cable glands, 6 to 12 mm2 (7 to 9 AWG) outer diameter cable


LCD back-lit display + smart keys
Display in video inverse in case of fault
Customizable by user (display 1 to 16 channels simultaneously, fixed or scrolling, on events...)
Bar graph with alarm threshold

Visual indicators:

7 LEDs per line
1 LED fault indicator


5 smart keys
1 audible alarm accept/reset button

Operating use

Operating temperature:

-20°C to +50°C

Storage temperature:

-20°C to +50°C


5 to 95% RH


100-240 Vac 50-60 Hz or 21-28 Vdc, 112 W max


Embedded back up power supply in option (0.6 Ah)


500 mA min (without module)

Measurement lines

Digital lines:

8 maximum
RS-485 communication, proprietary protocol, 9600 Baud
2 twisted shielded-pair cable

Analog channels:

8 maximum
0-23 mA analog signal input (4 to 20 mA reserved for measurement) 120 Ohm load resistance
2 or 3-core shielded cable

Voltage (typical):

21 to 28Vdc

Maximum current output per line:

1.2 A (1.5 A intermittently)

Maximum current output in total:

2.4 A permanent (3.2 A intermittently)


Per channel:

5 alarm levels (A1, A2, A3, Overscale, Underscale) + Fault
Non-ambiguity reading option for combustible gases monitoring

Programmable thresholds:

On instantenous ou averaged values, rising or falling alarms, manual or automatic acknowledgement

On-board relays:

5 fully programmable alarm relays
1 fault relay (non-configurable)
Dry contact relay
DPCO relays with contact rating of 250 Vca 2 A (inductive)

Digital outputs:

RS-485 Modbus RTU serial link



According to EN50270


EN50271 and metrological performances according to EN60079-29-1

Low Voltage Directive:

According to EN61010




20 years (4 lines, powered with 24 Vdc)
17 years (8 lines, powered with 24 Vdc)


According to Marine Equipment Directive 96/98/EC. Fulfills the EMC requirements for installation in General Power Distribution Zone and/or Deck Zone.