I have run my plasma CNC about 5 years, nursing “dry air” issues along the way.  All in all, I’ve always been able to get the job done.

Still using my original versions of Sheetcam and Mach 3.  SheetCam TNG v 4.0.10  Mach3 v R3.043.022

But in the last 48 hours I am at my wits end.  Everything freezes after the M03 command. (Bad air, bad consumables aside, none of my usual workarounds are working.)  The torch is on but does not proceed with the cut.
 
If I turn OFF the “THC ON/OFF” on Mach 3, the torch will proceed with cutting, but the results are beyond lousy.   
 
The THC is from PlasmaRoute CNC model PR301.  This THC unit is made by Sound Logic.  Cutter is a Thermal Dynamics A60 Cutmaster.

At this point I want to learn if my post processor is generating optimum code for the hardware and software configuration I am using.   Can I do anything different to have more reliable performance of my THC?  If anyone can chime in and let me know if I should be focused on SheetCam, or Mach3, or something else, I’d greatly appreciate the help.   

I’ve read the post at the following link, which is why I am asking about my settings:  https://www.machsupport.com/forum/index.php?topic=20303.0

Here is my post processor code and some pics.
Thanks!
N0000 (Filename: Sportsman Nested 48x48 P1.tap)
N0010 (Post processor: x_plasma_scribe140.scpost)
N0020 (Date: 10/24/2017)
N0030 G20 (Units: Inches)
N0040 G53 G90 G40
N0050 F1
N0060 (Part: Sportsman Nested 48x48)
N0070 (Process: Outside Offset, out, T6: Steel  12ga .105 volt 108 amps 40)
N0080 G00 Z1.0000
N0090 X12.3182 Y-0.7036
N0100 Z0.1800
N0110 G28.1 Z0.12
N0120 G92 Z0.0
N0130 G00 Z0.1400
N0140 G92 Z0.0
N0150 G00 Z0.1800
N0160 M03
N0170 G04 P1
N0180 G02 X12.4260 Y-0.7169 I0.0473 J-0.0605 F80.0
N0190 G01 X12.4349 Y-0.7283 F80
N0200 X16.7775 Y-6.2865
N0210 G03 X16.8001 Y-6.2930 I0.0158 J0.0123 F80.0
N0220 G01 X23.4281 Y-3.8806 F80
N0230 G03 X23.4413 Y-3.8611 I-0.0068 J0.0188 F80.0
N0240 G01 X23.1951 Y3.1880 F80
N0250 G03 X23.1806 Y3.2066 I-0.0200 J-0.0007 F80.0
N0260 G01 X16.4004 Y5.1508 F80
N0270 G03 X16.3783 Y5.1427 I-0.0055 J-0.0192 F80.0
N0280 G01 X12.4341 Y-0.7048 F80
N0290 X12.4260 Y-0.7169
N0300 G02 X12.2927 Y-0.7428 I-0.0796 J0.0537 F80.0
N0310 M05
N0320 G04 P0.5
N0330 G00 Z1.0000
N0340 X0.0000 Y0.0000
N0350 M05 M30

our machine with the same parts from the same company is doing the same thing.  what was your solution???

The good news is it had nothing to do with my hardware or post processor commands.  All of that runs fine, no configurations changed since original purchase and setup.

The main problem with my machine is that I had little to no water in my table.  (I am semi-retired now and moved my machine to my home shop.  In doing so, I added heavy casters to the legs and push the machine outside to do all my cutting.  The water made the table too heavy to move and I didn't care about the smoke as it was outside. )

After a lot of frustration, I added water back to my table, and most importantly, fill it to the top of the slats, until its about ready to start overflowing onto the floor.

With that done, as my torch tip begins to wear, causing the symptom to resurface, I'll adjust my pierce height lower.  For example, cutting 12 gauge mild steel with 40 amp tip.  The A60 pierce setting should be 0.18.  When the machine quits working, I change it to .14 and it starts cutting again.  As the tip wears further, I'll go down to 0.12, 0.10, and so on.  I've gone as low as 0.07.

With keeping the water level at its maximum height, my machine is running great again.  Just make the occasional pierce height reduction and I'm able to get all my jobs cut with little delay.

Hope this helps.  Took me a couple of months to figure it out.  I'm cutting more steel now than I ever have.

if you go to diagnostic Screen and have a look for Torch ON Signal.

If THC is on M3 macro is waiting for this Signal.