The MX 40 is a gas detection unit that communicates via radio to the BM 25 wireless units. This allows for the centralisation of all of the measurements recorded by the BM 25s in one location and the adjustment of settings.

The MX 40 controller can manage up to 16 wireless BM 25 units, including up to 32 measurement channels. A unit equipped with LEL, NH3 and O2 cells will occupy 3 measurement channels. Therefore, a maximum of 10 units of this type could be connected to the same MX 40.

The technology used is a mesh network. All hosts are interconnected with this type of network, forming a net-like structure. Each network node can receive, send, and relay data. This avoids the problem of sensitive points in the network, which would cut the connection to a part of the network in case of an outage. If a node is out of service, the neighbouring nodes will relay the messages via another route.

The maximum range between network nodes is 1000 meters, open-field. Because the same message can be relayed 4 times, the maximum distance between a node and an MX 40 unit can reach up to 5000 meters.

The frequency is 2.4 GHz. This frequency is the most popular because it is license-free in most places worldwide, unlike the 868 MHz and 900 MHz bandwidths. To be precise, communication is carried out on the ISM (Industrial, Scientific and Medical) radio band, which is located between 2.4 and 2.4835 GHz.

The I/O modules communicate over the MX 40’s RS485 network. They are mounted on the DIN rail on the MX 40 enclosure or may be located remotely, up to 1000 meters from the controller.