Starting over

Patrick Obrien wrote: Not in a while. I recall it wanted an 5i25 with another mesa card. G540 was not an option.

Because the pin allocation is set in firmware, and not HAL, it turns out that the HAL code is almost (and sometimes exactly) the same even if the firmware and physical pins change. So you can use the settings for a probotix breakout as long as your actual firmware is G540.

So, in PNCConf choose the 5i25 internal data and prob_rfx2 option (which is a simple dumb breakout). and choose "accept component changes"
Then configure connector 3. (which is the DB25 connector on the 5i25) and you will see "unused stepgens" numbered 0, 1, 2 and 3. Choose axes for these to suit how you want to wire the G540, for example 0 = X, 1 = tandem X, 2 = Y, 3 = Z.

I think that GPIO 000 is charge pump on the G540? If so then choose GPIO 000 as control-> charge-pump

This setup should be really very close:

Having followed this through, I see that you can't change the PGain fro 50 for the stepper PID. Is that the right number?

BigJohnT wrote:
Is the 5i25 flashed for the G540? The biggest problem people have are with the charge pump on the G540 which can be turned off.

If you have a lot of I/O you might consider a 7i76 or a standard breakout board attached to P2.

It came that way and I've redone it several times. I'm not against either but I get into trouble doing configuration tweaks. My logic was to use what everyone else is using on an 4 motor 3-axis and avoid the hole most rookie tweakers fall into.

I would love to have an I/O problem. Not there yet.

andypugh wrote: ... you can't change the PGain from 50 for the stepper PID.

You lost me there but I will give the above a try.

andypugh wrote:

Patrick Obrien wrote: Eventually I would suggest installing the 5i25 and upgrading LinuxCNC to 2.8 where support for systems with more than one motor per axis are significantly better supported.

Is there an iso for 2.8?

buildbot.linuxcnc.org/

You just have to change a couple of things in the Synaptic Package Manager.

JT