mach3 modbus or serial communication limitations

[jasminder]

Hello friends,
i want to control mach3 totally from external switches so obviously, the inputs and outputs of 2 ports are not enough. The one solution is modbus i guess.
I know a little bit of uC programming and use of their i/O and want to know where should i start with mach3 modbus. I want to know how it works and what are the limitations of using it. Can just two pins on the port can create a way between 20 switches and mach3?

i don't have any prior knowledge about serial communication. I don't even know if there is any difference between modbus and serial com.
Any help from there?

regards.
jasminder singh

[jasminder]

Or i was just thinking about hacking a keyboard to make a panel and use the oem triggers.

[BR549]

Why not simply use a standard or MINI  key board and setup hotkeys for your functions. I use an industrial keyboard that has 24 Fkeys and CAN do more with alternate hotkeys.

Or use the Pokeys usb I/O unit and add the keypad matrix switches (May require programming the I/o functions)

Why reinvent the wheel the old one rolls very smooth(;-) TP