Tweco SC-3000 - Manual (Page 71)

SC-3000
Manual 0-5100 A-1 APPENDIX
APPENDIX 1: DEFINITIONS
THC
Torch Height Control, in this case refers to the SC3000.
Initial Position Start
Input where Start from CNC is applied to start THC’s height finding sequence.
Ready (Start XY)
Input to THC for arc transferred signal from plasma (OK to Move).
Enable Ignition Plasma
Originally intended to start the plasma, now used to start preflow while finding height when that feature is
enabled (Operator Terminal Preflow set to non-zero)
Separate Ignition Plasma
Signal activates Start relay on PCB to supply isolated Start to plasma.
OK to Move-PS(plasma)
Signal from plasma indicating arc transfer has occurred. Is routed directly to the THC and indirectly to CNC
controller via OK to Move relay on PCB .
THC Pierce Delay
Time (parameter set on the operator terminal) following arc transfer that torch remains at pierce or elevated
height.
OK to Move (THC)
Signal from THC, active at end of THC pierce delay.
CNC Pierce Delay
Dwell time after CNC receives OK to Move from THC or Plasma before CNC starts torch horizontal motion.
THC Preflow time
Setting on Operator Terminal (OT) used for preflow during height finding.
THC Control delay
Often called AVC delay, this is time starting when torch is moved to cut height until THC starts controlling
height to the sampled arc voltage.