G code command through serial


Thank you for your support in advance.

I have MOOZ-3 and satisfy with.

Thesedays, i’m interesting to C# programming specially communication program.
In my understanding if i send proper G code command through COM port(USB) then MOOZ-3 will respond.
Depend on the command, what i’m trying to do is Z-axis down by 0.06mm
so i sent “G91 G1 Z-0.06 G90” but no respond at all.

do i need some specific header? or am i have wrong command for?
If anyone have similar experience, i need advice.
Thank you.