Chapter 2
NI 5450 Overview
©
National Instruments Corporation
2-39
NI PXIe-5450 User Manual
External Sample Clock Sources
The NI 5450 can accept an external clock to directly drive the Sample
clock. When using an external Sample clock, the frequency stability and
accuracy of the Sample clock is determined by the provided external
Sample clock.
The following figure shows possible Sample Clock paths.
You can set the clock source by calling the niFgen Configure Sample Clock
Source VI or the
niFgen_ConfigureSampleClockSource
function.
You can multiply the clock by an integer, W (or 1/W) by calling the
External Sample Clock Multiplier property or the
NIFGEN_ATTR_EXTERNAL_SAMPLE_CLOCK_MULTIPLIER
attribute.
When using an external Sample clock you should configure the Sample
clock rate by calling the niFgen Set Sample Rate VI or the
niFgen_ConfigureSampleRate
function.
Note
Refer to the device specifications for the allowable voltages, signal types, and
clocks that you can use for all external Sample clocks.
PXI_CLK10
CLK IN
High
Resolution
Oscillator
PLL
CLK OUT
(None)
Divide/M
Sample Clock
Timebase/M
PLL* W
with Phase
Adjust
Divide/N
Sample
Clock
Timebase
Channel
Delay
Channel
Delay
CH 0
Sample Clock
CH 1
Sample Clock
Divide/K
Reference Clock
External Sample Clock
External Sample Clock Timebase
