Chapter5
PCI-1711/1731 User’s Manual
Advantech Co., Ltd.
www.advantech.com
– 31 –
of ±10V to the reference input of the D/A output channel you want to
calibrate. Adjust the full scale of D/A channel 0 and 1, with VR3 and
VR4 respectively.
Note:
✎
Using a precision voltmeter to calibrate the D/A outputs is recom-
mended.
You can adjust VR3 and VR4 until the D/A channel 0 and 1 output
voltages approach the reference voltage (at least 1LSB), but with the
reverse sign. For example, if V
ref
is -5V, then V
out
should be +5V. If V
ref
is -10V, V
out
should be +10V.
5.4 Self A/D Calibration
We know, in most cases, it is difficult to find a good enough DC
voltage source for A/D calibration. We provide a self-adjusted A/D
calibration program “SELFCAL.EXE” to help solve this problem. The
steps of self-calibration are outlined as below:
1. Connect DA0_OUT to AI0.
2. Connect AGND to AI1, AI2, AI3, AI4 and AI5.
3. Run the SELFCAL.EXE program.
4. First calibrate the D/A channel. Adjust VR3 until the DA0_OUT
output voltage appr10V. Then press the SPACE key.
5. Next we will do the A/D calibration. Now the DA0_OUT output
voltage will be +9.995V, then adjust VR2 until the output codes
from the card’s AI0 focused on FFE (at least 70%) and adjust
VR1 until the output codes from the card’s AI1, AI2, AI3, AI4
and AI5 focused on 7FF (at least 70%).
6. Press the SPACE key to finish calibration procedures.
