thcud − Torch Height Control Up/Down Input
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loadrt thcud |
Torch Height Control This THC takes either an up or a down input from a THC
If enabled and torch is on and X + Y velocity is within tolerance of set speed allow the THC to offset the Z axis as needed to maintain voltage.
If enabled and torch is off and the Z axis is moving up remove any correction at a rate not to exceed the rate of movement of the Z axis.
If enabled and torch is off and there is no correction pass the Z position and feed back untouched.
If not enabled pass the Z position and feed back untouched.
Physical Connections typical paraport.0.pin-12-in <= THC controller Plasma Up paraport.0.pin-13-in <= THC controller Plasma Down parport.0.pin-15-in <= Plasma Torch Arc Ok Signal parport.0.pin-16-out => Plasma Torch Start Arc Contacts
HAL Plasma Connections thc.torch-up <= paraport.0.pin-12-in thc.torch-down <= paraport.0.pin-13-in motion.spindle-on => parport.0.pin-16-out (start the arc) thc.arc-ok <= motion.digital-in-00 <= parport.0.pin-15-in (arc ok signal)
HAL Motion Connections thc.requested-vel <= motion.requested-vel thc.current-vel <= motion.current-vel
Pyvcp Connections In the xml file you need something like:
<checkbutton>
<text>"THC Enable"</text>
<halpin>"thc-enable"</halpin>
</checkbutton> <spinbox>
<width>"5"</width>
<halpin>"vel-tol"</halpin>
<min_>.01</min_>
<max_>1</max_>
<resolution>0.01</resolution>
<initval>0.2</initval>
<format>"1.2f"</format>
<font>("Arial",10)</font>
</spinbox>
Connect the Pyvcp pins in the postgui.hal file like this:
net thc-enable thcud.enable <= pyvcp.thc-enable
thcud (requires a floating-point thread)
thcud.torch-up bit in
Connect to an input pin
thcud.torch-down bit in
Connect to input pin
thcud.current-vel float in
Connect to motion.current-vel
thcud.requested-vel float in
Connect to motion.requested-vel
thcud.torch-on bit in
Connect to motion.spindle-on
thcud.arc-ok bit in
Arc Ok from Plasma Torch
thcud.enable bit in
Enable the THC, if not enabled Z position is passed through
thcud.z-pos-in float in
Z Motor Position Command in from axis.n.motor-pos-cmd
thcud.z-pos-out float out
Z Motor Position Command Out
thcud.z-fb-out float out
Z Position Feedback to Axis
thcud.cur-offset float out
The Current Offset
thcud.vel-status bit out
When the THC thinks we are at requested speed
thcud.removing-offset bit out
Pin for testing
thcud.velocity-tol float rw
The deviation percent from planned velocity
thcud.correction-vel float rw
The Velocity to move Z to correct
John Thornton
GPLv2 or greater