Description and topology guidelines for connecting 1-Wire sensor bus.
In order to be able to ensure maximum reliability when having connectect as many sensors as possible, it is recommended to keep the following recommendations.
The 1-Wire bus in all UniPi devices does not use just one wire, but it uses two data lines to serialize the network in order to maintain maximum reliability. Based on that it is required to connect both data lines 6+7 and of course lines 5 (Vcc - 5V) and 8 (GND) according to the following picture.
The following picture describes connecting of 1-Wire devices when using our HUBs.
Please take into account that the bus is vulnerable to the environmen in which it is installed. In standard conditions it is able to handle 13 - 15 sensors while using just one channel. Maximum total length is about 200m in ideal conditions.
When dealing with reliability of the network (e.g. in case of nearby devices that emits high electromagnetic interference, like coils of contactors, frequency changers, etc.), it is recommended to use shielded STP/FTP cable to interconnect the network and connect its shielding to the ground of the building where the device is installed.
Due to serialized topology of the network it is necessary to follow the right order when connecting sensors (or other HUBs) as shown in the following pictures.
|Fully equipped HUB||Partially equipped HUB|
For detailed guidelines and specifications, please see information from the manufacturer.