Mesa 7i76e with G540

Hello,

I have a 3 axis router driven by 4 steppers (2 in tandem on the long axis). Using a Gecko G540 to drive the steppers. The machine was working fine using the parallel port to drive the G540.

With the 7i76e installed, and having run Pncconf, I'm getting super slow movement in the Z and X, in the wrong direction. So slow, it's barely perceptible, just clicking along. The Y axis doesn't seem to be moving at all.

From the reading I've done, I'm thinking the step and direction timing settings are wrong. I tried setting them to higher values, but it's still not working. Any ideas what I should try?

I also read that the G540 doesn't really have 10x micro-stepping, so I'm not sure what to set the Scale value at? In Pncconf I chose the 10x micro-stepping option.

I'm attaching my hal and ini files.

I disabled the charge pump on the G540 just to try to get the motion working first. I've found the recommended charge pump setup on other threads here. I'll add that in later.

Thanks for the help,
Jeremy

The default velocity is pretty slow (~8 mm/second)
What is you screw pitch?

The G540 should be OK with about 2.5 usec timings

How is the g540 connected to the 7I76E?

(the 7I76E is a somewhat odd choice to drive a G540, a 7I92 would normally make more sense since the G540 has an integrated parallel port type breakout)

I see velocity settings under DISPLAY, TRAJ, AXIS, and JOINT. Do they all need to match each other? I'll have to try adjusting them. To test the machine, I'm jogging it and using the slider to increase the velocity up to the max. When set to around 300 to 400 mm/min on the slider, I'm getting maybe 1mm/s movement on the Z axis, and less on the X. When I increase the slider to faster settings there is no movement at all, or imperceptible. And the direction is wrong on both X and Z when they do move.

The X and Y screw pitch is 10 mm, and Z is 4 mm.

I just quickly tried setting the 4 timing values to 2500 with no improvement, then tried adjusting the STEP_SCALE for no microstepping, which also didn't help.

I'll have to triple check my wiring to be sure I didn't miswire, but this is what I intended:
G540 DB25 to 7i76e TB2

---

2 - 3
3 - 5
4 - 9
5 - 11
6 - 21
7 - 23
8 - 15
9 - 17

Do I need to connect the GND pins on TB2 1, 7, 13, and 19?

I chose the 7176e because I want to use it with both the G540 and Leadshine drivers, as well as other future upgrade plans. I'm building another prototype machine with Leadshine drivers and want to be able to use the 7i76e to test that machine as well.

I forgot to mention, I'm using LinuxCNC 2.8.

I just tried updating my ini to set all default velocities to match each other, with Max set to 160 and Accel to 320.

I also continuity checked all the connections between the 7i76e and g540. They match what I posted above.

You _must_ connect the 7I76E ground pins to the G540 ground pins (G540 DB25 pins 18 through 25)

Thanks! Connecting those grounds fixed the motion problems. Now I need to invert the direction. I remember reading another post about that, I'll do a search.