Elan Digital Systems Ltd.
42
AD125 USER’S GUIDE
“<ZxxxU>”
Zero point at gain xxx in Unipolar Mode
“<FxxxU>”
Full scale point at gain xxx in Unipolar Mode
“<ZxxxB>”
Zero point at gain xxx in Bipolar Mode
“<FxxxB>”
Full scale point at gain xxx in Bipolar Mode
Zero point is defined in two ways :
i) for Unipolar mode it is the voltage applied to the card that causes the
ADC reading to be +½LSB±¼LSB when averaged over 1000 readings.
ii) for Bipolar mode it is the voltage applied to the card that causes the
ADC reading to be 0±¼LSB when averaged over 1000 readings.
Full scale point is defined as :
The voltage applied to the card that causes the ADC reading to be
F.S.-(½LSB±¼LSB) when averaged over 1000 readings where F.S. is
0x7ffh (i.e. maximum ADC output code).
The voltage coefficients are stored as ASCII floating point strings which
always occupy 9 characters e.g. “<F100B>+2.498000”. The gain range
is storred as 3 ASCII digits e.g. “050”=0.50, “200”=2.00 etc.
