ADC fault or ADC fail

The “A to D” fault means that two identical Analogue to Digital conversions produced the same count number. Normally this would be impossible unless the Analogue to Digital (A to D) converter is faulty or the voltage readings from the scale base is outside the range of the A to D converter.

Corrective actions

Disconnect the load cell cable from the back of the indicator, turn the indicator off and back on again. Does the A to D fault go away? Try connecting the operator panel to another scale base and check for the A to D fault message. If the Operator panel works with another scale base, without faulting with “A to D fault”, then this indicates that the signal voltage from the scale base is outside the A to D range.

If the fault is traced to the scale base as described above, then check that the load cell cable from the operator panel to scale base junction box is not cut or crushed (a crushed cable can cause the internal wires to short out). Swapping this cable between scale bases can be used to check the cable if suspected.

Also check that no wires have been caught between the edge of the metal junction box and the scale frame causing a short circuit. Also measure the voltage between the green and white wires (signal wires for the four load cells), which voltage should not be greater than 10 mV.