Some issues of using "Home All"(home all joints) when using Multi-ring Absolute

At present, I have built a xyz-ac machine tool and used RTCP function, which can work in both simulation and real lathe. I referred to the official 'xyzbc-trt-kins (switchkins)' example

The only difference is that HOME_ABSOLUTE_ENCODER = 1 means that the joint moves to HOME at the end of the homing sequence, whereas HOME_ABSOLUTE_ENCODER = 2 doesn't move at all,

You might have to experiment to see which works best with your kinmetics / switchkins system. But both should work.

Thank you andypugh!

I conducted tests on the machine

I added this line to the ini file
HOME_ABSOLUTE_ENCODER=2
press "home all"
Set the value of the absolute encoder at mechanical zero position to the G54 coordinate system
g10 l2 p0 x-208.621 y-133.6 z-300.0 a-87.85 c-85.18
Use G54 coordinate system

Non RTCP is correct and achieved my goal, but RTCP seems to be incorrect. It seems to use the zero value of the absolute encoder as the kinematic coordinate origin. Below are screenshots of these two situations



Now, I have some new issues

Is this a conventional method for using absolute encoders?
Before this, I thought we still needed to set the zero position of machine.
Now, I use the zero position of the absolute encoder as the zero position of the machine, even though this may be an unattainable position, it is not the coordinate origin of kinematics
 

The kinematics provides inputs to set the coordinates of your table rotary assembly.
This is from 'xyzac-trt.txt':

Hal Input pins:
xyzac-trt-kins.x-rot-point
xyzac-trt-kins.y-rot-point
xyzac-trt-kins.z-rot-point

X, Y and Z rot-point pins represent the
offsets of the center of rotation of the C axis
relative to the machine absolute zero

Add this to the [HAL] section of your ini file and enter your offset values as described above:

Thank you Aciera!

It works! now the xyz axis is correct in RTCP

But it doesn't seem to know that my A C axis value(a=-87.85 c=-85.18) are the absolute zero positions of the rotation axis

When I am at a-87.85 c-85.18, it does not consider me to be at the origin, but rather to have turned to a-87.85 c-85.18

I have looked at 'xyzac-trt.txt'. It seems that it does not have this parameter, the absolute zero setting of the A C axis, such as setting x/y/z-rot-point

What should I do next? Thank you for your reply

It's been a very long time since I have used absolute encoder homing but maybe try setting 'HOME_OFFSET' in the 'JOINT_n' section for A and C in your ini file.

Thank you Aciera!

Based on your method, I feel like I have completely solved this problem. Now, The machine is running correctly both Non RTCP and RTCP.
As a beginner, I did not understand the correlation between absolute encoders and HOME_OFFSET before this

Thanks again