1-Wire is a very low-cost bus system, which was mainly developed and used for the acquisition of temperature values.

Example: Pre-assembled 1-Wire sensor. Flexible use, from the hollow wall socket (behind the switch) to the outdoor area.



  • Easy setup via Plug and Play
  • Low cost
  • Minimum power consumption less than 1mW
  • Flexible cable laying

Characteristic data

  • Up to max. 32 sensors can be connected to one server.
  • Max. Total cable length 150 m
  • Various wiring topologies: star, line, tree structure


  • 5V supply voltage
  • data cable
  • GND


Verdrahtung 1-Wire

Optionally, 1-Wire can also be used in “parasitic mode”, i.e. in 2-wire operation. Then the sensor uses the data line as power supply. In this case, however, a maximum of 20 sensors can be used for a total of 50 metres.

When connecting the sensors, it is essential to pay attention to the colour coding on the label. This can deviate from the picture.

Star wiring


Max. 10 sensors with max. 100m in total

Line with short branches

Linie mit kurzen Abzweigen

Max. 32 sensors with 150m in total

Tree structure


Max. 25 sensors with max. 100m in total

Ring topology is not allowed!