What is get_tcp_force ? force at the tool flange or TCP?

Technical Questions
1

Hello, dear community.

I am developing a screwing tool and I using an external tool and the UR5e. I am a little confused about the get_tcp_force function.
This is my mockup
image

Does get_tcp_force return the external force/torque read from the sensor mounted in the robot tool flange?
or
Does get_tcp_force return the forces/torques reader from the force sensor in the tool flange and transform its values to the TCP that has been configured?

2

It uses the defined TCP but the result is in the Base frame.

image

To get that in the tool coordinate system, you’ll have to make the transformation:
https://www.universal-robots.com/articles/ur/programming/get-force-and-torque-values-in-tool-coordinate-system/

3

In the base frame is ok for me.
Do you know the equations that convert the data from the force sensor mounted in the tool flange and the TCP?