The 1-wire network is a communications bus system designed by someone(?) at Dallas Semiconductor (now part of Maxim Integrated) that provides low-speed data, signaling, and power, using up a total of one pin on the CPU no matter how many peripheral chips are on that bus. (Other ways of connecting a peripheral to the CPU either require another pin for each peripheral, or require more pins for the first peripheral, or both).
The 1-wire network is perhaps the most popular way to measure temperatures at many different locations and send that data back to one central processor.
Bich Pham. "One-Wire Serial Bus Carries Isolated Power And Data". http://electronicdesign.com/power/one-wire-serial-bus-carries-isolated-power-and-data The same circuit is also shown in "APPLICATION NOTE 3754: Single-Wire Serial Bus Carries Isolated Power and Data" http://www.maximintegrated.com/app-notes/index.mvp/id/3754 uses a MAX845 transformer driver and a transformer to send power and data from the host to the parasitic-power 1-wire device, and an optocoupler to send data from the 1-wire device back to the host.
Is it true that "IEEE 1451.4 uses the Dallas Semiconductor "one-wire" interface" ?