Erratic movement on power up that does not stop - [SOLVED]

[billyclaymyers]

So it seems the issue is resolved.

For the next person who is perhaps running into this issue, pay careful attention to the fact that on the GR214V Pin 6 of CN1 which is ground, has a different symbol than Pin 1 of CN2.

I was running 4 separate power supplies ( 1 24V, 1 5V, 2 48V ) with the 48V being for Pin 5 of CN1 for VDC+ on the GR214V.

The V- or Common side of all the power supplies was interconnected to the same star COM point. Apparently the 48V V- was either feeding back from the Raptor or something in that Power Supply was feeding noise. This was causing a fluctuation in COM resulting in a step being triggered erratically despite the GR214V being less susceptible to EMI.

I removed the 48V V- from the COM star point and attached it only to Pin 6 of CN1 via a different screw terminal bus. I left the 24V and 5V supplies V- connected to the COM star point so that they were sinking to the same ground signal. If you were to simply isolate the 5V V- to the Raptors and NOT interconnect it to the COM for the 24V feeding the Acorn then you would never get any steps as the two sources would not be sinking to the same COM.

Now, if you use the Acorn supply, then the issue noted above about sinking to different COM would not be an issue as they share a COM, but if you were to interconnect the V- from another supply which is feeding your Raptor's on the 18-80VDC input, you could potentially see the same issue.

Still not sure what is actually happening as I don't have a scope down where the machine is at, so I was unable to determine where the step was coming from, but upon examining the schematic for the GR214V, it became clear that these are intentionally separate ground. I should also note that the Acorn Schematic for the GR214V does not show the grounds connecting, but the wiring diagrams for all the Meanwell power supplies seem to indicate they all link back to earth ground, and so since the input shares a single earth ground, the idea that these would somehow be different or introduce error was not something I considered.

Thanks to @cnckeith for answering quickly.

Billy