How to invoke an error message to be displayed in Axis?

Suppose I have a python script running that will detect some sort of error condition, how can I get it to display a message in axis, much like the typical error messages displayed in the bottom right  for example "Can't do G1 without a feedrate"

If I need to do this from HAL, I should be able to get the Python script to activate a HAL pin.

Thanks,

Have a look at the 'message' component:
linuxcnc.org/docs/2.9/html/man/man9/message.9.html

Also see the linuxcnc python module.
linuxcnc.org/docs/devel/html/config/pyth...inuxcnc_command_code

look for:
display_msg(string)
error_msg(string)