National Instruments PXI-6561/6562 - Manual (Page 17)

© 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 k
Ω
NI 655X 50
Ω
or 10 k
Ω
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