Python status channel: Spindle speed value not working in G96 mode

[Sigma1912]

Tested in current master but it is also broken in 2.9 and 2.8. Not sure if it ever worked.

The status channel does not reflect the actual spindle speed (ie hal pin value 'spindle.0.speed-out') when in G96 mode, instead it contains the maximum speed set by the optional 'D' word or the default +/-1e30

[andypugh]

Recent commits have worked round this. (PR #3454 )
Do we still consider this a bug rather than the unexpected consequence of intended behaviour?

My current feeling is that it is a bug, and if it is clear that the value should reflect the HAL pin value rarther than the G-code value, then there may be a fix. However if it is meant to display the G-code value then perhaps we need to document that users of the value should consider also the the G96 status before using it?

[Sigma1912]

That's true, I have not thought of it that way. I don't think this was the intended purpose but here might be some value in having the maximum spindle speed in the status channel when using 'G96'. The actual spindle command is already reflected in the 'spindle.0.speed-out' pins.
If you want I can file PR to add some information to https://linuxcnc.org/docs/html/config/python-interface.html#sec:the-spindle-dictionary

[andypugh]

I think a comment suggesting that a user of the Python interface should check the spindle speed mode, if they have not themselves set it, would be good. I think that in most cases that if the Puthon code cares what the mode and speed are is, it will already know, and be setting it.

It might also be useful to document the actual numerical values of the G-codes (which are here: https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_internal.hh#L198 )

[Sigma1912]

completed