Hi all!

I've been using a duet 2 wifi board for a while and while it's pretty awesome, I do not have a PanelDue or any other button panel connected to it.
All interactions must be done remotely and it can be a little inconvenient at times.

So I've started a fun little project of building a diy panel that would let me do some basic things like perform emergncy stop, home the printer, load/unload fillament, etc.

It turned out that uart of duet panelDue port is mostly straightforward to use, which is fantastic.
I can send gcode commands to printer and receive replies with no issues.

Well, almost no issues.

Ran into a problem where 'M408' status command would not work if printer is busy (homing axis, executing macro, etc). A busy printer does not respond to the uart commands. This means I cannot get accurate printer status and having difficulties distinguishing between printer offline and printer busy states ( no reply either way).

What is the correct way of handling this situation? How does PanelDue do this? is there a Gcode command that perhaps returns a non-blocking response?