Hi Charles,
So from Post 214:
This is where Jogging X Z causes Spindle Command Voltage to shift by 77mV.Connected voltmeter to spindle drive high and low inputs. Commanded DAC4=100. Voltage at drive input checked -454mV, same as at Kanalog.
Jogged Z- from KMotionCNC. Drive input voltage went from -454mV to -528mV, then back to -454mV when jogging stopped.
Jogged Z+, voltage -531mV.
Similar results from X.
Spindle sped up slightly, no jerking.
Later I understood the voltage at the Kanalog end (DAC4 relative to Kanalog GND) also shifts by the same 77mv when Jogging.
I thought we performed a similar test with DAC4 commanded to zero and saw a similar shift magnitude when Jogging.
So the question becomes why is the DAC4's voltage shifting?
The test from your previous post shows no significant current being introduced. 29mV/120Ohms=0.24mA. Did the DAC Voltage also shift 70mV?
So maybe repeat the test with the DAC commanded to 0 and then 100 while verifying Jogging does cause a 70mV voltage shift and there is no significant current being injected.