Advantech MIC-3716 Manual page 122

discrepancy is less then 2 LSB.
4. Adjust the BIPOLAR offset voltage. First, write any value to
BASE+9 to clear FIFO. Then set the A/D channel to channel 0,
and to set the range as –5 V to +5 V.
5. Write the value from 0x0000 to 0x00FF sequentially to the
Calibration Command and Data register (BASE+18), and get
each bipolar range' s data by the software trigger A/D method.
Repeat this procedure 1000 times, then average those data for
each value. Check if the average data is close to 32767.5. If so, go
to the next step. Otherwise, you must change the value and repeat
the whole procedure in this step again until the average data is
close to 32767.5.
6. Adjust UNIPOLAR offset voltage. First, write any value to
BASE+9 to clear FIFO. Then set A/D channel to channel 0, and
set the range as 0 V to 10 V.
7. Write the value from 0x0100 to 0x01FF sequentially to the
Calibration Command and Data register (BASE+18), and get
each bipolar range' s data by the software trigger A/D method.
Repeat this procedure 1000 times, then average those data for
each value. See whether the average data is close to 32767.5. If so,
go to the next step. Otherwise, you must change the value and
repeat all the procedure in this step again until the average data is
close to 32767.5.
8. Adjust GAIN offset voltage. First, write any value to BASE+9 to
clear FIFO. Then set A/D channel to channel 2, and set the range
as -5 V to +5 V.
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