computer?

[kbenz]

My computer crashed. I'm still using the old dthcII with windows xp. Is XP still required or can I move up to newer versions of windows

[acourtjester]

If you need a parallel printer port, you will have a problem finding one but you can add a adapter card. You can Google refurb PC to look for a cheaper way to go. The last time I lost a PC I went with the AIO type as I had a ether connection to the controller card.

[kbenz]

ahh, so the parallel printer port is the holdup on updating the windows version?

[robertspark]

I think some of the newer or replacement parallel port cards are actually usb cards.... they won't work as they are unreliable as far as timing is concerned.

best to have a look at the plasmacam section or the forum as their older plasmacam machines need parallel ports and have some recommendations as to which are genuine replacement parallel port cards

[kbenz]

maybe it's time to upgrade. Prices aren't too bad on the website. need to figure out which one I need

[tcaudle]

Here is the deal with MACH3 and th e parallel port:
1. The whole idea of MACH3 was to use the parallel port as a high speed bidirectional device to do CNC. Normally windows does not let you get to the internal times that let you have high speed PRIORITY data to a part. Art "hacked " windows (XP) and that became the Parallel Port Driver. It also has fairly fast input speeds so it was usable for internal THC (external Up and Down Z joig signals)
2. The parallel port driver is for 32 bit systems so ANY WIN 6 64 won't work. WIN10 and up is all 64 bit. Yes I am aware that there is a "patch" that lets you run MACH3 in WIN10 but have not heard of any success doing it with old parallel port hardware . It does not work with certain hardware like the DTHCIV that has special drivers (plug-ins in MACH)
3. Over time computer manufacturers moved away from the parallel port (as did printer and external equipment vendors) . USB is not a continuous protocol and the bus is shared with all of the devices and so the communication is "bursty" and often delayed so it not usable to try and run a parallel port NEAR real time device. Any gaps in the data stream in MACH will cause bad things.

In later setups the parallel port was taken out of the mix and cards like the ESS were introduced. They use "buffers" so the data can be sent and queued up for the motion to be real time at the hardware but the code has already run on the PC. So any feedback has to be inside the motion loop , not back to the PC . Windows is like the really tall guy with he big hat that sits in front of you at the theatre....always in the way.

USB is great for some things; not for something that needs bidirectional real time data. its also limited to short distance and prone to errors from noise.

Sometimes there is just so much red on the lollipop!

[weldguy]

Thanks Tom, informative and funny post on the lpt port

[kbenz]

upgraded and cutting. Thanks tom and Jon

[tcaudle]

Great! I assume you see the vast speed and response improvements! Also the real time VAD anti dive,

You might consider reducing your XY acceleration down to 20 . It will make the VAD work better and things move smoother . NACH needed to have as high an acceleration as it could support because it had no VAD and would corner dive as it slowed down to take turns. The "cure' for that was to simply let the toolpath go off the actual trackh (round corners and even cut across them) This kept up speeds and helped with the diving but at the expense of accuracy . CommandCNC has an accuracy setting (Tracking tolerance) that is actually a G-Code Parameter that is embedded from the POST.

KEEP OIN CUTTIN" !

[kbenz]

Thanks Tom, I'll check the xy acceleration. everything has been going great. Big difference from the old system. Quite pleased