I'm thinking about switching back to EMC (EMC2)

Harry_Y wrote:

From what i am reading it is basically an I/O card that is fully configurable
like a Parallel port only better

It is more and less, than that.

It does on-board step-generation, PWM generation and encoder counting, all up to MHz frequencies, like the other Mesa cards.
So, it can emulate what a parallel port would look like connected to a computer with 100nS latency (20,000nS is more usual).
It can also be configured to be individual IO lines, or to connect to various daughter cards (such as the 32 + 16 GPIO, encoder, stepper, spindle-drive 7i76)
However, Unlike the other Mesa FPGA cards it is not possible to switch the onboard configuration file from within EMC2. (You can set pins to be inputs and outputs, but not change which stepgen/encoder/pwm modules are loaded)

One available configuration will wire direct 1:1 to a Gecko G540 though.

There are two ports on the board, (the second is on a header and needs a scond backplate) you can have different configs on each port

I guess the only common thing to a parallel port is the use of the DB25 cable... it's more plug and play. I have the 5i25 7i76 combo that I'm putting in my plasma cutter. It is real new so a few bugs remain in the firmware/software but I'm excited about them. Being a FPGA based programmable I/O card for the PCI bus the speed is so much faster than a parallel port solution it is mind boggling.

If your wanting to do threading you might be better off just grabbing 3 of the G251's (iirc the one with the terminal block and heat sink) and pair that up with the 5i25 7i766 combo. This way you have an encoder input for your spindle which is required for threading.

John

Well the G251 5i25 7i76 route you get all the I/O including spindle and encoder on the 7i76 and don't pay for the fancy package and extra G251 that the G540 has. In the end you need to do the math and figure out which one fits your needs better.

John

Harry_Y wrote:

Between the Mill and the Lathe I have 6 axis that I would lie to drive

Mill X,Y,Z, A - Lathe X,Z

As you can't use them all at the same time with one PC, you could do all that with just a parallel port. I had my mill/lathe set up that way at first. I had one of the outputs switch a relay to control which spindle was active. I had the advantage that mill X was lathe Z and Mill Y was Lathe X, so there were only 4 stepper drives in the system. I am not clear if your configuration is like that. It was just a case of opening a different configuration file which set which parport pin (and hence stepper) each axis controlled. If you have 6 stepper drives then you can probably send the step/dir to both drives, but only enable the one you want to move.

Having said that, I felt very cramped by the lack of IO, and switched to a 7i43 pretty quickly.

Any suggestion on which Mesa card I should use.

5i25 and 7i76 looks like a great combination.

You might also want to look at the Pico Universal Stepper Controller, that has good EMC2 support too.
www.pico-systems.com/univstep.html
The Pico card handles 4 axes, the Mesa 7i76 handles 5 axes. You will need to double-up or use some switch logic with either configuration.