Nathan,
Here is a picture. In order from left to right, Vin is power supply (reg 24V), OutB/OutA go to DC brushed motor, GND is tied to power supply ground and to daughter board, 5V supplies sensor on daughter board, and daughterboard sensor outputs 0-3.3V (relative to gnd) into A1. ERR is out to 3.3V relay.
I thought the error described below was a similar issue, after reading more closely it is different as I cannot see the error in the motor control center.
The motor controller works otherwise, I’ve just had to disable the error detection. I’ve got a handful of these boards on hand and if I drop a new one in its place it works as expected. The one that has the issue is probably about 3 years old.