Python Help - Keep track of tool in spindle.

Hi All,

I'm trying to get this python script to work so that I can keep track of the tool in the spindle and if Linuxcnc closes for whatever reason the information is retained.

My issue is despite commanding the offset using:
cmd.tool_offset(old_tool,
                    s.tool_table[old_tool].zoffset,
                    s.tool_table[old_tool].xoffset,
                    s.tool_table[old_tool].diameter,
                    s.tool_table[old_tool].frontangle,
                    s.tool_table[old_tool].backangle,
                    s.tool_table[old_tool].orientation)

Linuxcnc is reporting s.tool_in_spindle = 0, despite at the bottom edge of the screen in axis it shows the correct tool, offset, and diameter. and I need something like an M61 Qxx for the tool_in_spindle to show a value. What is also weird is if I do an ATC change my GCode based changer is able to find the correct tool using #<_current_tool>.

Thanks in advance.
(Linux CNC 2.8.1)
 

Close Linuxcnc, with a tool loaded.

When you re-open Linuxcnc you will see it will set the tool in axis. Then once it enters the loop it will write tool 0 to the file because despite axis showing a tool loaded offsets and all. The tool in spindle value is 0.

That or open and close linuxcnc 3 times in a row. The third opening tool will always be 0.

I'm not sure if this is related or not.
in qtvcp and gladevcp we manipulate the tool file outside of linuxcnc.
When we saved the tool file - some times the OS will not save it right away - it caches it.
os.fsync() can force the OS to save the file right away.

also to update the VAR file, we needed to to a switch to Manual mode then back to MDI mode

Both of these created hard to track down, inconsistent errors.

Chris

Thanks for your feedback Chris, in this case the status.tool_in_spindle is returning 0 even though linuxcnc accepted the command to update the tool info.

I’d just MDI up a M61 but it can’t issue MDI commands until the user homes the machine.

try
NO_FORCE_HOMING = 1

in the TRAJ section

No, I need it to force homing. If the user forgets it will crash the ATC into the side of the spindle. 

I wish certain MDI Commands didn’t require homing, or there was a force MDI switch. 

You can home the machine on shutdown or save the machine position ny butting a POSITION_FILE = position.txt in the [Traj] section

Unfortunately, I don't think that would work with the mesa 7i40 drivers, as the encoder counts are cleared from the FPGA at startup. Plus there is no way to be 100% sure the machine didn't move while being powered down. It's not a big piece of iron so someone could definitely bump the table .010"-.020". I'm trying to hold .001" +/- between homes.

Does anyone know if this is a bug or is my implementation wrong? I guess I could wait for the machine to be homed and then issue a G61 to finish the job. Then update the text file. Seems a little wonky...

Why don’t you just remap m6?
and write an simple mcode in bash to write the new tool in a file
or save it in an persistent parameter.