Free no upgrade hookup in my area
New thermostats (especially the ones with LCD screens, Wifi, etc.) have larger power requirements and rely on the C wire to provide a return path for power coming from the R terminal.
USB, short for Universal Serial Bus, is an industry standard that defines cables, connectors and communications protocols for connection, communication, and power supply between computers and devices.
There are cables with A plugs on both ends, which may be valid if the cable includes, for example, a USB host-to-host transfer device with 2 ports, but they could also be non-standard and erroneous and should be used carefully.
and also place the flexible contacts, which wear out sooner, on the easily replaced cable, while the more durable rigid contacts are located in the receptacles.
So this must mean the thermostat is currently wired correctly and the W2 is indeed for the two-stage heating.
Almost every thermostat installation manual I've read always says something along the lines of "Make sure to mark you wires based on the currently connected thermostat. The colors are really just a guideline, there is no requirement to adhere to them.
The 12 Mbit/s data rate was intended for higher-speed devices such as disk drives, and the lower 1.5 Mbit/s rate for low data rate devices such as joysticks.
The USB 2.0 specification was released in April 2000 and was ratified by the USB Implementers Forum (USB-IF) at the end of 2001.
USB cables have the plugs, and the corresponding receptacles are on the computers or electronic devices.
In common practice, the A end is usually the standard format, and the B side varies over standard, mini, and micro.
I'd start by looking at your furnace and seeing where the wires are plugged into - take a picture of that end as well.