thc − Torch Height Control |
loadrt thc [count=N|names=name1[,name2...]] |
Torch Height Control using a Mesa THC-AD board. The voltage signal from the plasma torch is converted to a frequency by the THC-AD board. This frequency is fed to an encoder. The velocity output from the encoder is fed into the THC component. The tip voltage rises as the distance increases. While testing no change is made to z_pos_out it is just passed through While enabled and torch is on when x+y velocity is above minimum add correction to current z position. While enabled and torch is off and z is raising up remove any correction as the torch moves up. |
thc.N (uses floating-point) |
thc.N.volts-setting float in |
Torch Volts Set Point (SP) |
thc.N.p-gain float in |
The Proportional Gain (Kp) |
thc.N.i-gain float in |
The Integral Gain (Ki) |
thc.N.d-gain float in |
The Derivative Gain (Kd) |
thc.N.enable bit in |
Enable the THC, if not enabled Z position is passed through |
thc.N.chl-enable bit in |
Enable the Corner Height Lock |
thc.N.vel-tol float in |
Percent of Velocity Deviation 0.00-1.00 |
thc.N.spindle-on bit in |
Motion Spindle On |
thc.N.arc-ok bit in |
Arc OK from Plasma Torch |
thc.N.encoder-vel float in |
Velocity Output in User Units per Second from Encoder |
thc.N.set-vel float in |
the commanded velocity of XY |
thc.N.x-vel float in |
Used to compute velocity |
thc.N.y-vel float in |
Used to compute velocity |
thc.N.z-pos-cmd float in |
Z Motor Position Command In |
thc.N.z-pos-out float out |
Z Motor Position Command Out |
thc.N.x-y-velocity float out |
The X + Y velocity |
thc.N.volts float out |
The calculated Volts |
thc.N.vel-out float out |
The velocity reading from the THC |
thc.N.p-out float out |
the Proportional Term correction |
thc.N.i-out float out |
the Integral Term correction |
thc.N.d-out float out |
the Derivative Term correction |
thc.N.correction float out |
the total correction |
thc.N.smoothed float out |
the Input after smoothing |
thc.N.at-speed bit out |
On when within tolerance of speed |
thc.N.test float out |
used for testing |
thc.N.vel-scale float rw |
The scale to convert the Velocity to Volts |
thc.N.scale-offset float rw |
The offset of the velocity input at 0 volts |
thc.N.volt-dist-scale float rw |
The Voltage Distance Scale |
thc.N.volts-tol float rw |
The Voltage Tolerance. |
thc.N.i-cap float rw |
The maximum Integeral error. |
thc.N.input-gain float rw |
The maximum change between inputs |
John Thornton |
GPL |