MESA 5i25 + 7i85S

Thanks for the suggestions. I verified that the FPGA is flashed with 5i25_7i85sx2.pin. I was able to get all motors moving by changing step and direction wires to the /TX0 and /TX1 pins rather than the TX0 and TX1 pins. Gecko drive common to gnd on the 7i85s.

I still don't understand why going through pncconf and configuring with zero encoders creates PID pins and parameters. I don't' have encoder feedback and I selected "commanded" position feedback versus "actual" position in the pncconf setup screen.

The PID values definitely do something. I tried changing the default values and had a deleterious effect on my motor movement.

I thought the PID parameters were only for setting up a closed loop servo or stepper system.

All LinuxCNC stepgens are closed loop, in that they have a digitally
controlled oscillator to generate the steps with a position loop controlling
the number of steps generated.

You can use the built in position loop in the driver or use an external position
loop with a PID hal component (external in that its built with hal components)

There are advantages and disadvantages of both methods. The PID method is
quite a bit more robust with regard to host timing jitter and more tunable than the
driver position mode so that's why its used here.