Host_client usb header load switching

[Md Mubdiul Hasan]

Hello everyone,

Kindly help me in the following circuit to understand the action,

This is a header circuit to make a bridge between device and host.
Lets say Magconn connector( https://www.hackster.io/OscarSeo/getting-started-with-magconn-6ecbd3 ) is  Device-A and CN1 is Device-B.
When the 2 devices are connected, VBUS would be same on both side ( no matter VUSB is comming from device -B).
At this time ID signal from device-A will be floating in host mode. Not sure ID signal from CN1 will be floating or grounded!

Question arises in my mind,

1. CN1 connector is a micro usb male, which connect my device to the one side of header.
2. Transistor Q3  is being biased from +usb 5V, is responsible to turn Q1 OFF in case on input overvoltage?
3. Not sure why extra 1-7 wire is connected afetr Q1, then U1 active high IC is powered by VBUS ?
4. Not sure how the M_SIG signal is used here, the magconn connector connect with just a magconn header with host. Kindly explain it in detail.
5. By the U3 IC, how the active load is acting ?(NO datasheet found)
6. If the host is not connected I think VBUS will be not available in P+ test point, right?
7. Do you think, D+,D-,ID signals can be show in scope, if both device are connected?

Help me please.