M-Bus Mikro-Master

Mains-independant M-Bus master with USB-Interface for mobile installations and readout of small M-Bus systems with a Laptop.

  • Max. 10 slaves

  • Baudrates: 300 to 9600 Baud

  • Bus cut-off at overload and short-circuit condition

  • USB-Interface

  • Power supply by Laptop 

  • USB cable (length = 1m)  in the delivery package

  • Laptop as mobile temporary master

  • Easy installation of M-Bus systems

  • Good for M-Bus demonstrations

  • Current USB driver from the chip manufacturer

A special version for PSION handheld computers is available on request.

The ServiceMaster

The M-Bus Mikro-Master is a complete M-Bus level converter, specially designed for mobile use. The device is supplied from the USB interface, which makes an external power supply unnecessary. This and its small housing recommend the Mikro-Master USB especially for service purposes such as meter parameterization, commissioning of installations or troubleshooting. For small networks of up to 10 meters, the MikroMaster USB is also suitable for permanent use in the installation. In combination with a laptop it is the ideal tool for every service technician and should not be missing in any toolbox.

Technical Data

Operating Voltage

5VDC ±5%

Power Consumption

max. 1,5W

Temperature Range

0 .. 55 °C

M-Bus Voltage (without load)

28V (Mark)
16V (Space)

M-Bus Idle Current

max. 15mA
(10 Unit Loads)

Overcurrent Threshold


Internal Bus Resistance

app. 100 Ω

Bus Extension

max. 500m (J-Y(St)-Y nx2x0,8)
(10 slaves at the end of the cable)

M-Bus Baud Rate

300 .. 2400 Baud
with suppression of echo

Galvanic Isolation



Light-grey plastic bax
Protective class IP40
H x L x W: 30 x 54 x 110 mm


USB 2.0 Socket Typ B
M-Bus: 2-pin socket for pluggable screw terminal


Order Information

Order Number



Micro-Master incl. adapter cable (NO LONGER AVAILABLE!)


Micro-Master USB incl. USB cable

Additional Accessories

Order Number



M-Bus readout software with automatic meter search and CSV export


M-Bus read out software, available in various license amounts

Copyright© 2018  Relay GmbH

Designed By T.McDowell