I used Mach3 for a long time, but only with 2 LPT Ports.
Now, I want to use Mach3 to control more motor, pump and to solve Interference-proof problem.

How can I use Comp port, I heard about Homann Board, but, I don't know exactly which board I must buy ?

If I want to make a connect board via COM PORT by myself, there are any problems ? any schematic ?

Thank!

(Sorry for my English, I'm from Vietnam).

If you want to expand your system, and bring it right up to date, I would say get the SmoothStepper board.

This is a new board that runs from a USB port. It controls all the axis, and has enough imput and output connection for anything you want. It also controls the "stepping" for the motors, so your computer does not have to do that, and is much smoother and faster.

If you already have your machine connected to the computer, the SmoothStepper is a direct swap for the LPT1 and other outputs, but only has the one connection - a USB plug.

The SS wont provide any more connection than 2 Parallel ports do, well it will provide two inputs for encoders as well but thats it.
 A com port can be used for serial ModBUS with devices such as Peter Homann's ModIO, I use serial ModBUS with my PLC and I think there are ther ways to connect devices through serial. You will NOT however be able to connect axis through the serial as the timings are not good enough ( or thats my understanding)
 If you are needing lots of digital I/O then have a look at the PoKeys, Art has just done a plugin for it so its deeply beta as far as Mach is concerned, it connects via USB. Again anything that is timing critical can not be controlled via it as I think there can be a variance of 100mS.
Hood

Sorry forgot to give you a link to the PoKeys
www.poscope.com

Hood

All motors which I use is AC servo motor ( Mitsubishi and Yaskawa servo),  can  SmoothStepper controll servo motors?

Mach3 can use with USB Port ? how can I do that ?

Best regard !

Yes Servos work well with the SS, basically the SS is an external pulse engine (bit more than that but.... )  so if your drives accept Step and Direction then the SS will control them. Good thing however is the SS can pulse at 4MHz so no need for electronic gearing in your servo drives
 Yes Mach can be used with USB, you will need to either use a device that already has a plugin written such as the SS or be capable of writing your own plugin to control your own device.
Hood