1-Wire
1-Wire is a very inexpensive bus system, which was developed and is mainly used for the acquisition of temperature values. Example: Pre-assembled 1-Wire sensor. Can be used flexibly, from the cavity wall box (behind the switch) to the outdoor area.
Advantages
Easy setup via plug & play
Cheap
Minimum power consumption less than 1mW
Flexible cable laying
Characteristics
- Up to max. 32 sensors can be connected to one server.
- Max. total cable length 150m
- Different wiring topologies: star, line, tree structure
Connection
- 5V supply voltage
- Data line
- GND
Wiring
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. However, in this case a maximum of 20 sensors at 50 meters can be used.
When connecting the sensors, it is essential to pay attention to the color coding on the label. This may differ from the picture.
Line topology
Max. 10 sensors with max. 100m in total.
Star topology
Max. 32 sensors with 150m in total.
Tree topology
Max. 25 sensors with max. 100m in total.