© National Instruments Corporation 17 NI Digital Waveform Generator/Analyzer Guide
Dynamic Acquisition
When performing dynamic acquisition with the NI 654X/655X, the source
generating the signals needs a matched source impedance as close to 50 Ω
as
possible to minimize signal reflections and maintain optimal signal quality.
Figure 7 shows a diagram of a dynamic acquisition system using the NI 655X
as an example.
Figure 7. Dynamic Acquisition Functional Diagram
Note
NI digital waveform generator/analyzers have various input
impedance settings, as shown in the following table.
Refer to the NI Digital Waveform Generator/Analyzer Help for more
information about signal termination.
Table 3. Supported Impedance Settings
Device Supported Input Impedance
NI 654X 10 kΩ
NI 655X 50 Ω or 10 kΩ
NI 656X
*
100 Ω for channels configured for
LVDS operation; 10 k
Ω for channels
configured for single-ended operation
*
NI 656X cables use 100 Ω differential impedance rather than 50 Ω single-ended
impedance.
NI 655
X
NI CB-2162
R
S
R
T
Peripheral
Device
50 Cable
