Mesa 6i25 W/ PMDX-126 BOB

I'm looking at switching from mach3 to linuxcnc and have a couple questions. I have a Mesa 6i25 card and the PMDX-126 BOB. I know I can get linuxcnc to work with just the pmdx bob but I also want to use my 6i25 card.
So the question I have is does anybody have a bit file that matches the pinouts for my BOB? My pinouts are:

Pin 1 - Coolant
Pin 2 - X Axis Direction
Pin 3 - X Axis Step
Pin 4 - Y Axis Direction
Pin 5 - Y Axis Step
Pin 6 - Z Axis Direction
Pin 7 - Z Axis Step
Pin 10 - Emergency Stop

Pin 11 - Limit Switch - Optional
Pin 12 - Limit Switch - Optional
Pin 13 - Limit Switch - Optional

Pin 14 - Spindle Direction
Pin 16 - Spindle Speed (PWM)

Pin 17 - Charge Pump Output - Optional

I have looked over some of the bit files and the 5i25_r990x2.pin file looks close to my pinouts. The only difference is the Spindle Direction is pin 16 and the Spindle PWM is pin 14. Also can the pins that are not used in the bit file be assigned to anything?

Thanks Luke

Pins that are not used (like unused PWM, encoder, or stepgen pins) can be used as GPIO as long as they
are the last pins of a sequence

( This is consequence of the driver only being able to enable instances 0 through N of a particular module )
So for example if you had a bitfile that had 5 stepgens on P3. you could disable the fourth and fifth stepgen
to reclaim their pins as GPIO, but you could not disable only stepgen 1 (without disabling 2,3,4,5 )

For the spindle control it turns out that you can swap the PWM and direction outputs by selecting the
PWM gens locked-antiphase mode (in software)


You might require a custom bitfile if the chargepump signal needs to be high frequency (>500 Hz )
since its just a GPIO bit, 500Hz is what you will get if you toggle it at the servo thread rate (1 KHz )

In the 5i25_r990x2.pin file it list the pins as:

IO Connections for P3
Pin# I/O Pri. func Sec. func Chan Pin func Pin Dir

1 0 IOPort None
14 1 IOPort PWMGen 0 PWM (Out)
2 2 IOPort StepGen 0 Dir (Out)
15 3 IOPort None
3 4 IOPort StepGen 0 Step (Out)
16 5 IOPort PWMGen 0 Dir (Out)
4 6 IOPort StepGen 1 Dir (Out)
17 7 IOPort None
5 8 IOPort StepGen 1 Step (Out)
6 9 IOPort StepGen 2 Dir (Out)
7 10 IOPort StepGen 2 Step (Out)
8 11 IOPort StepGen 3 Dir (Out)
9 12 IOPort StepGen 3 Step (Out)
10 13 IOPort None
11 14 IOPort QCount 0 Quad-A (In)
12 15 IOPort QCount 0 Quad-B (In)
13 16 IOPort QCount 0 Quad-IDX (In)

Can the pins that have NONE as a secondary function be programmed in software? How would I go about using pin 10 as a emergency stop?
Also pins 11-13 says QCOUNT as the function. What is that? Thanks for your help guys. I'm excited to use linuxcnc it should be a bigger improvement over mach.

QCOUNT means quadrature counter (for spindle encoder typically)

All pins can be programmed in software if the secondary function is turned off.
so for example if your linuxcnc hal/ini file specified num_encoders=0, pins 11,12,13
would revert to GPIO (software controlled)

If your hal/ini file specified num_encoders=0 num_stepgens=0 num_pwmgens=0
all pins would be GPIO

Also the unassigned pins (Port None) are there to be used as GPIO, such as limit switches, E-stop in or out, or what ever else you can dream up.

Yes all pins _can_ be GPIO, if they dont have a secondary function (none) they can _only_ be GPIO