Axbb-e poor linkage when pc is on same power group

[seense]

Hi,

I recently received a Axbb-e and got it all hooked up. All working fine but the only trouble I am having is that the blue LINK LED is a bit flashing once in a while and it sometimes looses connection and the vfd/stops. I did several tests and it only has this behaviour when the pc which communicates with the Axbb-e is connected to the same power group. I put a decent effort in the star grounding of all cable shields and components. Besides it had the exact same behaviour when the shielding wasnt connected yet. There is no EMI filter yet.

Now the easy fix is to just leave the pc on another group but I'd like to understand the issue. It's not that the small HP Compac I5 2400 draws too much current I guess? Would putting the control electronics behind an EMI filter sort the problem?

[cncdrive]

Because the ethernet connection is fully isolated therefor the noise which could effect the AXBB-E logic part is only through the 5Volts power supply which powers the AXBB-E. So, I would verify that powersupply, it is likely too sensitive to noise.

[seense]

Can I reduce the noise with an emi filter or should I change the PSU? It's the small 5v PSU from cncdrive.

[seense]

EMI filter just before the VFD seems to do the trick. Apparently together with the PC it caused too much noise.