Appendix D
– 45 –
PCI-1721 User’s Manual
Advantech Co., Ltd.
www.advantech.com
The auto-calibration program AutoCali.EXE helps you finish the D/A
calibration procedure automatically. Although the procedure is not
necessary, the following calibration steps are provided below for your
reference in case you want to implement the calibration yourself:
1. To adjust those four jumpers JP6~JP9 to 0~20 mA.
2. Setting the output range as 0~5 V for channel 0.
3. Adjust UNIPOLAR offset calibration. First, output
0x0000
to
channel 0. Then writing the value from
0x00
to
0xFF
sequentially
to Calibration Command and Data register (BASE+26H), and to
see whether the output voltage is less then 1 LSB. If so, to go to
next step. Otherwise, you must change the value and repeat all the
procedure in this step again until the output voltage is less then 1
LSB.
4. Adjust GAIN 5V calibration. First, output
0x0FFF
to channel 0.
Then writing the value from
0x00
to
0xFF
sequentially to Calibra-
tion Command and Data register (BASE+26H), and to see whether
the output voltage is less then 1 LSB. If so, to go to next step.
Otherwise, you must change the value and repeat all the procedure
in this step again until the output voltage is less then 1 LSB.
5. Setting the output range as ±10 V for channel 0.
6. Adjust BIPOLAR offset calibration. First, output
0x0800
to
channel 0. Then writing the value from
0x00
to
0xFF
sequentially
to Calibration Command and Data register (BASE+26H), and to
see whether the output voltage is less then 1 LSB. If so, to go to
next step. Otherwise, you must change the value and repeat all the
procedure in this step again until the output voltage is less then 1
LSB.
7. Adjust GAIN 10V calibration. First, output
0x0FFF
to channel 0.
Then writing the value from
0x00
to
0xFF
sequentially to Calibra-
tion Command and Data register (BASE+26H), and to see whether
the output voltage is less then 1 LSB. If so, to go to next step.
Otherwise, you must change the value and repeat all the procedure
in this step again until the output voltage is less then 1 LSB.
8. To change to another channel and repeat steps 2 to 7 to calibrate all
four channels.
