Up to 256 devices can be connected to a single 1-Wire bus, but the maximum number of devices that can be practically connected depends on the bus capacitance, wire length, and noise considerations.
To ensure reliable communication over long distances, use a twisted pair or shielded cable, keep the bus capacitance low, and use a 1-Wire bus repeater or a 1-Wire hub to amplify the signal.
The VPP pin is used to program the EPROM memory of the DS2431P+. It is not necessary for normal operation and can be left unconnected if programming is not required.
Yes, the DS2431P+ can be used as a standalone temperature sensor. It has an internal temperature sensor that can be read using the 1-Wire protocol.
A 1-Wire bus reset can be implemented by pulling the DQ pin low for at least 480 μs. This resets all devices on the bus and prepares them for a new transaction.
DS2431P+ datasheet
by Maxim Integrated Products
