User`s guide

Description
The Agilent 34411A/L4411A provides a pretrigger feature that allows
collection of the data being digitized before the trigger. This command
reserves memory for pretrigger samples up to the specified number of
readings (samples) to be taken before the trigger.
It is recommended that all triggered measurements be made using
an appropriate fixed manual range. That is, turn autorange off
(SENSe:<function>:RANGe:AUTO OFF), or set a fixed range using
the SENSe:<function>:RANGe, CONFigure, or MEASure command.