Thc turns ON and torch shuts OFF

[rife]

I have a DTHCIV that has been working great until it didn't. Program starts, after touch off, torch moves to pierce height, fires and as soon as the THC turns on, the torch shuts off and program stops....Good ground, good consumables...programs that previously worked don't work.. a setting ? board went bad ? If I run a test (torch off) it will run the code. Not sure where else to look...besides here.

[LNVM2020]

Hello,
If you can make a video to can help you will be useful.
After torch firing machine moves to cut and after thc turns on the torch shuts or it shuts without moving machine ?
First probability check your arc tension and increase it and for second probability maybe your time percing is too long decrease it.

[weldguy]

The problem is not likely with the THC.

When the THC turns on, do you notice the torch rise just before the torch shuts off?

What plasma cutter are you using?

[rife]

The torch shuts off on the DTHC "on" command line in the G code...After Piercing at .15 and moving down to cut height .06, as soon as the DTHC line of code is read is when it shuts off...the programs I have tried have been run many times before. I don't see it rise. I'm using book settings and it has worked in the past.

[weldguy]

Gotcha, that is very strange if your just running gcode that has worked in the past and it's not just happening with code that has just come from the post processor.

Not familiar with your system but is there an LED indicator that lights up when the torch is active? If so I am curious if that LED goes OFF or just the torch goes OFF, or both.

What plasma cutter are you using?

[rife]

Hyprtherm 65...Yes it says torch active and torch and indicator both shut off..There is no fault code but the "error" box says "DTHC is on"..It seems to be random too because sometimes it will cut as normal but not very often.. frustrating to say the least.

[AREA]

Any chance that something changed when post processing or is nothing your running freshly processed and this is happening with previously good gcode?

[TJS]

Have you tried cutting with the THC off and see what happens. You can also put it in manual on command CNC screen and toggle it on and off to see if it truly is the THC. So you can test simple straight line cuts and see what it does when turned back on.
I have found sometimes the 4 port hub gets disconnected and I have to unplug it and plug it back in. Should be two red lights on it for it to be online. Also what does the message/error screen denote.

[rife]

Hyprtherm 65...Yes it says torch active and torch and indicator both shut off..There is no fault code but the "error" box says "DTHC is on"..It seems to be random too because sometimes it will cut as normal but not very often.. frustrating to say the least.

[rife]

Have you tried cutting with the THC off and see what happens. You can also put it in manual on command CNC screen and toggle it on and off to see if it truly is the THC. So you can test simple straight line cuts and see what it does when turned back on.
I have found sometimes the 4 port hub gets disconnected and I have to unplug it and plug it back in. Should be two red lights on it for it to be online. Also what does the message/error screen denote.

this is an old ESP II A controller.. I don't have a 4 port hub. What is the difference between THC and DTHC ? In Settings, The toggle button says THC on/off, under that it says " not DTHC".. When I turn it off, the program will run, gantry moves but torch doesn't fire.. On the program run screen I have never been able to turn off the THC. Does the torch need to be lit for that to work ?

[rife]

Any chance that something changed when post processing or is nothing your running freshly processed and this is happening with previously good gcode?

Previously working cut files.

[rife]

I just ran a test..a circle with three holes in it. If I unplug the ethernet cable from the controller, try to cut the test part, the torch won't fire. If I plug it back in(Without doing anything else) the torch fires and it will cut the test part including the three additional pierces with no hiccups.. Some sort of a script error ??

[TJS]

Have you tried cutting with the THC off and see what happens. You can also put it in manual on command CNC screen and toggle it on and off to see if it truly is the THC. So you can test simple straight line cuts and see what it does when turned back on.
I have found sometimes the 4 port hub gets disconnected and I have to unplug it and plug it back in. Should be two red lights on it for it to be online. Also what does the message/error screen denote.

this is an old ESP II A controller.. I don't have a 4 port hub. What is the difference between THC and DTHC ? In Settings, The toggle button says THC on/off, under that it says " not DTHC".. When I turn it off, the program will run, gantry moves but torch doesn't fire.. On the program run screen I have never been able to turn off the THC. Does the torch need to be lit for that to work ?

Sorry. I thought you had command CNC set up.

[rife]

I changed the DTHC response time in sheetcam to 0.. Now the torch fires, shuts off like before but the gantry completes the circle then moves to next circle, fires and completes the rest of the program like it should

[weldguy]

Awesome. Glad you have it fixed and thanks for posting your solution. Odd that you could run the different setting before and now you have to change it but whatever works.

[rife]

My last post wasn't saying it was working but I believe I got it now, it was a bad ethernet cable... Thanks for your response. Sometimes when things don't make sense, they just don't.

[tcaudle]

something doe snot add up. I don;t think that is an Ethernet system . Its definably an old MACH3 based controller and probablye a parallel port (from he PC ) interface? There were some CAT5 cables from DTHC to PWm but with no 4 port hub it tells me the DTHC was a DTHCII or older DTHC. That model is reaching EOL (End of live) . We are running out of spares and parts to fix that older unit . Might want to consider an upgrade before June1 after which the pomades for that series will no longer be available.

[tcaudle]

Just a note: The DTHCIV you listed at the start HAS to have a 4 port hub for the RS485 connect to it to load settings and to receive screen values back. So that is how I surmised it was not a DTHCIV.

If it IS a DTHCIVyou HAVE to have a rs485 hub and connection. IF the DTHC IV loses connection tot he PC vai the hub the torch will shut off . Ther eis a watchdog signal FROM the hub that would go away if the hub locks up or the signal path is bad

So it MAY be that it IS a later model and has the DTHCIV and it has to have an RS485 hub to use the DTHCIV

In that case it COULD be an Ethernet connected controller and parts and upgrades are good for several more years