Keysight Technologies 3458A Guide D'utilisation page 194

5 Digitizing
Figure 5-3 Digitizing measurement connections
For most digitizing applications, the multimeter enters its high-speed mode
whenever sampling is initiated. In the high-speed mode, the multimeter becomes
completely dedicated to taking samples. This means that it will not process any
commands until the specified number of samples are completed. When samples
are sent directly to the output buffer in the high-speed mode, the multimeter
waits until each sample is removed from the output buffer before placing the next
sample in the output buffer. This ensures that samples will not be lost because of
bus/controller speed limitations. (When not in the high-speed mode, the
multimeter writes-over any sample still in the output buffer when a new sample is
available.) For more information, refer to
194
High-speed mode in
Keysight 3458A User's Guide
Chapter 4.