Basic Documentation

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Siemens M-bus level converter and M-bus web server A6V11157985_en--_f
Smart Infrastructure Engineering 2021-06-21
4.4 Power supply
4.4.1 Level converter WTV531.., WTX631..
Please note when designing the power supply for the level converter, that M-bus
devices require additional current of up to 20 mA when communicating.
For M-bus address conflicts during commissioning, multiple M-bus devices can
draw power at the same time and it adds up.
The level converter limits power on the M-bus to a maximum of 200 mA.
Select an AC/DC 24 V power supply with at least 12 W and voltage tolerances as
described in the technical data.
The level converter WTX631.. can also be used as the power supply for the M-bus
web servers WTV676.. .
4.4.2 Web server
Select an AC/DC 24 V power supply with at least 14.5 / 15 VA and voltage
tolerances as described in the technical data.
DC 24 V can be tapped from the power supply WTX631.. The web server can be
powered with this voltage without the need for a separate transformer.
Note