Is there anyone out there who has a functioning UMI-7764 and can easily tell me what the impedence across the +5V input to ground (where you'd hook up the power supply) is, assuming that the box is not hooked to anything else?
I'm trying to debug a problem where my stepper motors are not receiving the step signal and it seems that my grounds are getting yanked around such that the when the stepper motor output goes low the optocoupler on the stepper motor input does not register the step. We believe we've traced the problem back to the UMI-7764, and we're measuring ~80 Ohms across the +5V input, which seems rather low. I'm trying to confirm that it is, in fact, rather low before I RMA the box.
Thanks,
Jason
