I just got a CnC laser and when trying to set it up my x-axis is backwards. when i click the button to move it left it goes right and vice-versa. I had the same issue with my Y-axis until I changed the $3 to $3=3. my $$ code is
$$
$0=10
$1=255
$2=0
$3=3
$4=0
$5=0
$6=0
$10=0
$11=0.010
$12=0.002
$13=0
$20=0
$21=0
$22=0
$23=0
$24=25.000
$25=500.000
$26=250
$27=1.000
$30=1000
$31=0
$32=0
$100=80.000
$101=80.000
$102=100.000
$110=3500.000
$111=3500.000
$112=100.000
$120=100.000
$121=100.000
$122=10.000
$130=600.000
$131=800.000
$132=200.000