Hi
this is my first post
Please can anyone help me with getting values from system variables?
I am building a machine to grind stump grinder teeth and am trying to learn G code as I go.
Although nothing like a Mill I am using Machmil profile
So far I have managed to get over lots of problems as they came up
But I am stuck
I am using an optical switch as a probe to find depth of Z axis (to determine wear on cutter to be ground)
I am running Mach3 (Version R3.043.062) with a USB breakout board
The digitizer light comes on when the switch is triggered
When I try to read #2002 for the z position I get zero
I have included some sample code
When the machine runs the cutter moves till the light on the switch comes on then returns
And then moves the z axis to 2

g21
#50=3
a4.5 f200
g1 x193 y2 f600
g1 z1
g4 p1
g31 z20 f200
#50=[#2002+2]
g4 p1
z1.25
z#50
m30
(null line to load code)

I have looked at the forum chats and no one else seems to have trouble reading system variables
Am I being dumb or doing something stupid?
Please help

bet you have a Far Eastern USB board installed not setting the 2002 pound var is typical ie they do not work for probing in the 99.99% of them

IMHO get a smooth stepper USB if you must but Ethernet is better

Hi thanks for the reply
Yes it is a far eastern  board but I would have thought that if the digitizer light comes on then mach3 would be doing the variable setting internally

If the value is not stored in VAR(2002) then there is a good chance that it is stored in OEMDRO(802).

Tweakie.

Thanks Tweakie
I have now tried looking at #802 and still got zero.
I seem to get zero from any system variable
any more suggestions?

OEMDRO(802) is not a system variable in the same sense as #802. It is usually read within a VB routine as GETOEMDRO(802).

Tweakie.

I am not doing to bad with gcode but vb script is a bit beyond me at the moment.
I will try to get some help with it

#50=[#2002+2]

What is the +2 about?

Have you tried it this way :-

#50=[[#2002]+2]

I have now tried #50=[[2002]+2] still moving to 2 (so 0+2)
The plus 2 was because at one point I had it working and the value I got back was 2 higher than the z position I assumed some kind of probe compensation that I could not find.
the time it worked was after a new install but I have tried that again since and no joy.

if Tweakie is still seeing this
I now have enough vbscript to display variables in a message box.
But I do not understand the results.
the #2002 #5023 and oemdro(802) all read zero
if I assign a value to #5023 either before or after the g31 code then I get the value that I have assigned.
I don't know what else to try