I was having trouble with the stability of the motor and began troubleshooting. I have stripped down everything to open loop mode and using the Roborun application, setting the motor command value while monitoring the command and power on the chart. The motor runs smoothly except occasionally the power graph drops from the command value of 550 to 200. I have narrowed this down to only happening when the voltage is between 11 and 12V. Concerned there where voltage drops due to the switching I repeated this with the motor unplugged; same results. I also tried using both channels set at 550 and they both simultaneously and exact same values tracked each other through these glitches. Again in this case with no motors connected. Raising the voltage above 12 the problem goes away. I then added battery voltage to the chart and reset the max min values. The lowest value recorded was well above the 10V low voltage limit.
I set the low voltage limit from 10 to 8V and the problem has gone away. It appears that this is due to the voltage limit being triggered at some level below the serial interface. What is the response of the drive when the low voltage limit threshold is reached? Is this possibly a case of noise on the voltage measurement tripping this logic?