I have a Fadal15XT and am trying to balance a new Y-axis amplifier card that I have installed. I need the G-code to perform a straight diagonal move that loops un-interrupted while I adjust the gain and signal screws in the board. This is as far as I have got and this stops after one cycle.

%
O1
M6
M49
M98
G0 X5.0 Y5.0 S3000 M3 E1
G0 Z11.0
G1 Z11.0 F50.
X-5.0 Y-5.0 Z3.0 F150.
X5.0 Y5.0 Z11.
M99
%

Apparently I need an M49 that cancels out an over-ride and M99 for a loop command. Can anyone tell where I am going wrong?