B&B Electronics PCI-1711 - Manual - Manual (Page 50)

Chapter 5
– 42 –
PCI-1710 series User’s Manual
Advantech Co., Ltd.
www.advantech.com
A/D Calibration
Regular and accurate calibration procedures ensure the maximum
possible accuracy. The A/D calibration program ADCAL.EXE leads
you through the whole A/D offset and gain adjustment procedure. The
basic steps are outlined below:
1. Connect a DC voltage source of +9.995 V to AI0.
2. Connect AGND to AI1, AI2, AI3, AI4 and AI5.
3. Run the ADCAL.EXE program.
4. Adjust VR2 until the output codes from the card’s AI0 are focused
on FFE (at least 70%), and adjust VR1 until the output codes from
the card’s AI1, AI2, AI3, AI4 and AI5 are focused on 7FF (at least
70%).
5. Press the SPACE key to finish A/D calibration.
D/A Calibration (for PCI-1711 only)
The D/A calibration program DACAL.EXE leads you through the
whole D/A calibration procedure.
You can select the on-board -5V or -10V internal reference voltage or
an external voltage as your analog output reference voltage. If you use
an external reference, connect a reference voltage within the range 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
recommended.
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 Vref is -5V, then Vout should be +5V. If
Vref is -10V, Vout should be +10V.