The load current is measured by the shunt resistor using AD7193. We observed an AD value of 0xffffff under no load at the site. After that, when a load current of 10A is passed through the returned device, an AD value of about 8A is observed. The calibration was done before shipping, and the correction value in ROM was the same as the value before shipping.
The question is
(1) Is there anything other than out of range or VREF abnormality that becomes 0xffffff?
(2) What are the factors that cause the output to be low for a load of 10A?
VREF is high / low, etc.