zero an axis before every move

[ASC]

Hey guys, I'm working on a rather unique 5 axis dispensing machine and am still quite new to Mach and VB, so I'm having a difficult time with what is probably a simple problem.  I have a dispenser controlled by my C-axis that is moved in and out of the work area via a linear actuator.  This actuator is moved into place with the M-command M802 (switching output 1).  My goal is to have the C axis reset to zero every time the actuator is activated.  This is to simplify the g-code when programming the dispenser;  Rather than accumulating a larger and larger value each time a small amount of fluid is dispensed, we want to start from zero each time.  Can anyone help me with a VB script or any other approach to make my C axis zero each time I activate M802?

My M802 script currently looks like this:

ActivateSignal(output1)
code("G4 P1")

I just need some help on what lines to add to set the C axis to zero!

[BR549]

try

Dobutton(13)

[ASC]

And away she goes!  That did it perfectly, thank you! 

[Mc2]

try

Dobutton(13)

Hey guys, I'm working on a rather unique 5 axis dispensing machine and am still quite new to Mach and VB, so I'm having a difficult time with what is probably a simple problem.  I have a dispenser controlled by my C-axis that is moved in and out of the work area via a linear actuator.  This actuator is moved into place with the M-command M802 (switching output 1).  My goal is to have the C axis reset to zero every time the actuator is activated.  This is to simplify the g-code when programming the dispenser;  Rather than accumulating a larger and larger value each time a small amount of fluid is dispensed, we want to start from zero each time.  Can anyone help me with a VB script or any other approach to make my C axis zero each time I activate M802?

My M802 script currently looks like this:

ActivateSignal(output1)
code("G4 P1")

I just need some help on what lines to add to set the C axis to zero!

I would rather keep it simple. You will want to move the C axis incramental. So the g-code would look something like:

G91
C .01 f1.
G90

This way, you could move the actualtor back to the start when you are done. No need to reset zero. The C axis will move the set amount each time not a known postion each time.

Jim.

[ASC]

That would work but I need to have all the other axes moving in absolute coordinates at the same time I'm dispensing.  I'd be worried that the inremental change would cause an absolute headache.

[Mc2]

Oh, I understand. You will want the C axis moving simultaniously with other axis. In this case then I would use a macro varible. I would have to do some testing but it would go something like:

(At start of program)
#500=0.0

(anywhere in program where you wanted the feed move)
#500=[#500+.05]
G1 X1.0 Y1.0 C#500 F1

Anyways, glad you found your answers.
Jim.