National Instruments Low-Cost Multifunction I/O Board for ISA Lab-PC+ - Manual (Page 81)

Calibration Chapter 5
Lab-PC+ User Manual 5-8 © National Instruments Corporation
Unipolar Output Calibration Procedure
If your analog output channel is configured for unipolar output, which has an output range of 0 to
+10 V, then offset calibration is not needed. Calibrate your board by completing the following
procedures for gain calibration.
Adjust the Analog Output Gain
Adjust the analog output gain by measuring the output voltage generated with the DAC set at
positive full-scale (4,095). This output voltage should be V
+fs
±
0.5 LSB. For unipolar
output,
V
+fs
= +9.99756 V, and 0.5 LSB = 1.22 mV.
For analog output Channel 0:
a. Connect the voltmeter between DAC0 OUT (pin 10 on the I/O connector) and AGND
(pin 11).
b. Set the analog output channel to +9.99756 V by writing 4,095 to the DAC.
c. Adjust trimpot R1 until the output voltage read is +9.99756 V.
For analog output Channel 1:
a. Connect the voltmeter between DAC1 OUT (pin 12 on the I/O connector) and AGND
(pin 11).
b. Set the analog output channel to +9.99756 V by writing 4,095 to the DAC.
c. Adjust trimpot R3 until the output voltage read is +9.99756 V.