User`s manual

Using MINimum
and MAXimum
Parameters
You can execute many commands (like [SOURce:]FREQuency[1][:CW|:FIXed])
using the
MINimum or MAXimum parameters instead of a number value.
However, when using the parameters, the commands are immediately
executed when received. This happens even if the commands are coupled to
other commands in a coupling group. This is different than sending the
commands with number values, where the commands are executed after a
new coupling group is sent.
Thus, if a group of coupled commands are sent where the
MINimum and
MAXimum parameters conflict with the current AFG setting, the AFG
generates an error. This happens even though the commands that follow
may set the AFG to a state that does not conflict with the
MINimum and
MAXimum parameters.
For best results, use values in the commands and do not use the
MINimum
and MAXimum parameters.
Chapter 2 Generating Standard Waveforms 81