Acorn and Accelus drive connections.

[centroid467]

Did you set the drives to have the inputs pull up?
Disconnect the drive from the Acorn and verify that you see 5V across the inputs to the power supply ground.

Is "Signal Ground" from drive J3 pin 10, 12, 13, 15, or 16 tied to the Acorn power supply ground?

Please post pictures of the wiring to the drives and Acorn.

[RonRindahl]

Did you set the drives to have the inputs pull up?
Yes, screenshot attached.

Disconnect the drive from the Acorn and verify that you see 5V across the inputs to the power supply ground.
Not clear what you want me to check here.

Is "Signal Ground" from drive J3 pin 10, 12, 13, 15, or 16 tied to the Acorn power supply ground?
Pin16 is tied to Acorn H2-Comm connection. H2-Com shows continuity to power supply Com.


Please post pictures of the wiring to the drives and Acorn.

Photos attached

I did some more metering today and do see 0.007 volts on step pin while jogging the axis across H2-ST2 and H2-Comm. Also found a better Oscilloscope type meter in my Snap-on meter. Noticed a small change of state on it across the same pins while jogging.

[centroid467]

Disconnect the drive from the Acorn and verify that you see 5V across the inputs to the power supply ground.
Not clear what you want me to check here.

I did some more metering today and do see 0.007 volts on step pin while jogging the axis across H2-ST2 and H2-Comm. Also found a better Oscilloscope type meter in my Snap-on meter. Noticed a small change of state on it across the same pins while jogging.

Sorry, I should have worded that better. I wanted you to verify that the drive inputs are indeed pulled up to 5V with a voltmeter. To do that measurement, I would unplug the cable from J3 and measure from J3 pins 3, 4, 5, 17, and 18 to J3 pin 15 or 16.


I am starting to suspect they are doing something odd with inputs 5 and 6 when set up as pulse reference. On closer reading of the manual, it states to use "active output devices (i.e. CMOS, TTL). This implies that maybe the line driver outputs on the Acorn's DB25 header should be used. I apologize for not noticing that sooner.

For your Y axis drive, try wiring J3 pin 4 to Acorn DB25 pin 5 and J3 pin 3 to Acorn DB25 pin 4.

[RonRindahl]

For your Y axis drive, try wiring J3 pin 4 to Acorn DB25 pin 5 and J3 pin 3 to Acorn DB25 pin 4.

Moving J3 pins 3 and 4 over to the DB25 connector has it jogging now. I left the configuration in the CNC12 wizard set as it was with motor configured with screw connections. Still using Enable and COMM wires on the screw terminal header.

So out of curiosity, what is the difference between the DB25 and Screw terminal connection signals? Also, do they fire in unison regardless of whether you select "Screw Connection" or "DB25" in the wizard?

Thank you so much for you help.

[centroid467]

Glad that is working!

Yes, they do fire at the same time but one outputs low while the other outputs high. I think the selection in the Wizard is more for controlling the logical inversion on the signals that drive both sets of outputs. I would recommend setting the Wizard to DB25 and verifying that the Axis Signal Inversion settings on the Advanced Axis Configuration page are correct.

The screw terminals use open collector outputs and require a pull up. The DB25 outputs are TTL compatible CMOS drivers outputting 5V. The output logic levels are inverted because a high signal to the CMOS drivers outputs a high signal while a high signal to the open collector makes the transistor conduct, thus pulling the signal to ground.