Hello,
maybe somebody know, why THC function not working in Mach3 with USB cards? Why THC can work only with LPT port? What Mach3 need to start work?
Thanks in advance
An external motion controller card (USB/ethernet) usually has a plugin written for Mach3. A plugin is a peice of software that you install "inside" Mach3, and it tells Mach how to "communicate" with the external card. The card must have been designed specifically for THC use. If it hasn't been designed for that use it won't work. It's a bit like trying to open a spreadsheet in a word processor. It won't work because the word processor was not designed for that.
Your 2nd question has a similar answer. Mach was designed with the parallel port as it's main high speed I/O portal. The THC functionality was designed around the parallel port. Mach3 THC only works with the parallel port because it was designed that way.
Google for "UC300" or "UC-300". I believe that USB card has THC functionality but contact the manufacturer first and ask questions to see if it's suitable for you. If that board is suitable for you, then I think you must also add a breakout board to it if you want optical isolation.
If you want to learn more about the built-in THC functionality in Mach3, then check out the older Mach2 manual:
http://www.machsupport.com/wp-content/uploads/2013/02/Mach2Mill_6.11.pdfOne option you have it to actually use the parallel port. Buy a dual parallel port card for one of the computers PCI slots. In Mach configuration you can set the second parallel port to make pins 2-9 as inputs, giving a total of 13 inputs on that port alone. You would then need to find breakout boards for your two parallel ports, that will give you the needed 24v levels.