Figure b-1. ai/sampleclock and ai/convertclock – National Instruments NI 6232 User Manual

Page 148

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Appendix B

Troubleshooting

NI 6232/6233 User Manual

B-2

ni.com

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 Voltage Input Signals

section of Chapter 4,

Analog

Input

.

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

section of Chapter 4,

Analog

Input

, for more information.

How can I use the AI Sample Clock and AI Convert Clock signals on
an M Series device to sample the AI channel(s)?

M Series devices use ai/SampleClock and ai/ConvertClock to perform
interval sampling. As Figure B-1 shows, ai/SampleClock controls the
sample period, which is determined by the following equation:

1/sample period = sample rate

Figure B-1. ai/SampleClock and ai/ConvertClock

ai/ConvertClock controls the convert period, which is determined by the
following equation:

1/convert period = convert rate

This method allows multiple channels to be sampled relatively quickly in
relationship to the overall sample rate, providing a nearly simultaneous
effect with a fixed delay between channels.

Channel 0

Channel 1

Convert Period

Sample Period

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