The bottom of the Input waveform exceeds the VinMin value for this configuration. This will result in this signal being
clipped off, since the A/D Converter will saturate and return only VinMin. Second, VinMax greatly exceeds the high peak of
this input signal. This won’t result in an error, but it indicates that the measurement window isn’t well adapted to this input.
Increasing Snsr_Offset will reposition the measurement window, bringing Vin
Max closer to the input high peak, as well as
lowering Vin
Min below the input low peak.
Consider this case, where the selected Gain is too high.
Input clipping due to Gain
The Snsr_Offset is selected appropriately, but the Input_Range is too narrow. As a result, input signal amplitude exceeds
Input_Range and we will read clipped values at both the high and low end. Verifying that Input_Range exceeds the sensor
input AC amplitude is the most important factor in determining Gain.
In order to use the GnBiasOvride correctly, select a Gain such that Input_Range exceeds the AC amplitude of the input
signal (Equation 1), and then select a Snsr_Offset to ensure that the measurement window defined by Vin
Max and VinMin
contains the sensor input completely (Max. and Min. Voltage Definitions).
242 GEH-6855_Vol_II GEH-6855_Vol_II Mark VIeS Functional Safety Systems Volume II
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