PCIE-1840 User Manual
18
3.3.3
PCLD-8841 Signal Connection
To ensure the accuracy of PCIE-1840 would not drift by time, periodical calibrations
are necessary to make the performance match its specification. PCIE-1840 provides
two methods for calibration, manual-calibration and self-calibration with PCLD-8841.
By manual calibration, PCIE-1840 could achieve higher accuracy but it takes more
time and is suitable for the users who require a single channel calibration. Self-cali-
bration with PCLD-8841 provides a convenient way for user to calibrate all input
ranges. Both calibrations are required to be done after ambient temperature is stable.
Twenty minutes warm-up after PCIE-1840 begins running is necessary. Doing cali-
bration periodically can ensure the accuracy is the same over time.
Figure 3.5 PCLD-8841 board diagram for Auto-calibration
3.3.3.1
Self-Calibration
Self-calibration provides a convenient way to calibrate all input ranges with the assis-
tance of PCLD-8841. Before starting self-calibration, users need to fine-tune PCLD-
8841 output to make sure the reference voltage is accuracy. Users should connect
VOUT to a high precision multi-meter, at least 6-1/2 digital meter, and tune the eight
on-board variable resistors to the dedicated voltages. The following table lists the
functions of these variable resistors.
Table 3.2: PCLD-8841 Reference Voltage Output Tunning
Variable Resistor #
Dedicated Voltage (after tuning)
Corresponding Calibration
VR1
9.9 V
20 Vp-p, Gain Error
VR2
4.95 V
10 Vp-p, Gain Error
VR3
1.98 V
4 Vp-p, Gain Error
VR4
0.99 V
2 Vp-p, Gain Error
VR5
0.495 V
1 Vp-p, Gain Error
VR6
0.198 V
0.4 Vp-p, Gain Error
VR7
0.099 V
0.2 Vp-p, Gain Error
VR9
0V (GND)
ALL, Offset Error
Summary of Contents for PCIE-1840
Page 1: ...User Manual PCIE 1840 4 ch 16Bit 125 MS s High Speed Data Acquisition PCI Express Card ...
Page 4: ...PCIE 1840 User Manual iv ...
Page 12: ...PCIE 1840 User Manual 6 ...
Page 13: ...Chapter 2 2 Installation ...
Page 18: ...PCIE 1840 User Manual 12 ...
Page 26: ...PCIE 1840 User Manual 20 ...
Page 27: ...Appendix A A Specifications ...
Page 35: ...Appendix B B Block Diagram ...