RelAir R2M

Wireless M-Bus to M-Bus gateway for more than 60 meters.

  • Wireless M-Bus according to EN 13757-4 Mode S, T und C
  • Frequency 868 MHz
  • OMS conform and compatible (Spec 4.X.X)
  • supports M-Bus application layer acc. to EN13757-3, not DLMS / SML
  • Optional encryption Mode 5 or 7, AES
  • Power supply via M-Bus (6 unit loads) or USB
  • Whitelist with up to 63 meters configurable
  • Configuration with free Software via M-Bus or USB
  • Internal antenna, optional external antenne (only ProX-Version)
  • 2 housing variations Home, Professional

The RelAir R2M allows you to integrate up to 63 Wireless M-Bus meters into your existing M-Bus installation. For this purpose the OMS-compliant gateway stores the meterdata and answers a request by the M-Bus master with the last answer telegram. Because of the configurable whitelist it is of course possible to run several RelAir R2M in one M-Bus network. Due to the integrated mini USB interface the RelAir R2M can also be used as a full operational Wireless M-Bus Master. Our new gateway works without an external power supply and is either powerd from the M-Bus (6 unit loads) or via the USB interface.

Technical Data

StandardsEN13757-4, EN13757-3 and EN13757-2, compatible to OMS
Receive modesS1,T1,C1 (unidirectional) / Frame Format A and B
Application layerM-Bus acc. to EN13757-3 / not DLMS, SML
EncryptionMode 0 (no encryption), Mode 5 or Mode 7
Radio Scan List

up to 488 devices

Whitelistup to 63 devices, can be configured
Power supply

from M-Bus (6 unit loads)
or operation via USB (max.90mA)

Temperature range0 to 40°C (Pro/ProX), 0 to 55°C (Home)
Humidity10% to 70% (not condensing)

Housing RelAir R2M PRO

     MountingWall mounting
     MaterialPolystyrene, light grey
     B x L x H93 x 93 x 55 mm
  Protection class

IP54, IP65 is possible if the cable entry is done carefully

Housing RelAir R2M HOME
     MountingWall mounting or mounting on an in-wall box (60mm)
     MaterialABS, white
     B x L x H

80 x 80 x 25

Protection classIP40


Ordering information

Ordering number



Wireless M-Bus to M-Bus Gateway,
housing for living rooms, internal antenna

RelAir R2M PRO

Wireless M-Bus to M-Bus Gateway,
industrial housing, internal antenna


Wireless M-Bus to M-Bus Gateway,
industrial housing,
SMA socket for external antenna (not included)


USB-cable A to mini B 5-pin, length = 1,8 m


Magnetic mount antenna 868 MHz with 1,5m cable
for Wireless M-Bus, SMA male connector


Wall mountable antenna 868 MHz with 1,5m cable
for Wireless M-Bus, SMA male connector, IP66 waterproof