clunks / missing steps - DM856 and single pulse operation

[EddyCurrent]

Having read you previous posts I am surprised you say this

As I said before the PIC is powered from a plug-in 9VDC power supply, which is connected to the same 230VAC source as the 68VDC PSU which powers the motor / driver.

because it doesn't matter about that, it's the output dc grounds that have to be connected.

[dsc]

Why is that? what I meant to say is that eventually it all comes down to the same 230VAC connection, so ground on both should be at the same potential. Or am I missing something obvious?

Regards,
T.

[FatFreddie]

Why is that? what I meant to say is that eventually it all comes down to the same 230VAC connection, so ground on both should be at the same potential. Or am I missing something obvious?

It doesn't quite work like that, it's sort of complicated depending on earthing arrangements etc but you definitely need the DC grounds (maybe a bad term - DC 0v is better) connected.

[EddyCurrent]

Well I was surprised because it looks like you know what your about but it may be I'm at cross purposes.
I'm on about this.


But I then realised you might be saying this;

"I'm using the same power supplies for both the DM856 and the HBS86 tests"