National Instruments Data Acquisition Device E Series User Manual page 247

Appendix C Troubleshooting
E Series User Manual
reference the signal to the same ground level as the device reference. There
are various methods of achieving this reference while maintaining a high
common-mode Rejection Ratio (CMRR). These methods are outlined in
the Connecting Analog Input Signals
AI GND is an AI common signal that routes directly to the ground
connection point on the devices. You can use this signal if you need a
general analog ground connection point to the device. Refer to the
Differential Connection Considerations
Input, for more information.
How can I use the AI Sample Clock and AI Convert Clock signals on
an E Series device to sample the AI channel(s)?
E Series devices use the ai/SampleClock and ai/ConvertClock signals to
perform interval sampling. As Figure C-1 shows, ai/SampleClock controls
the sample period, which is determined by the following equation:
Channel 0
Channel 1
The ai/ConvertClock signal controls the convert period, which is
determined by the following equation:
This method allows multiple channels to be sampled relatively quickly in
relationship to the overall scan rate, providing a nearly simultaneous effect
with a fixed delay between channels.
section of Chapter 2,
section of Chapter 2,
1/sample period = sample rate
Convert Period
Sample Period
Figure C-1. Interval Sample
1/convert period = convert rate
C-2
Analog Input.
Analog
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