Keysight 34420A - Page 214

4 Remote Interface Reference
210 Keysight 34420A User’s Guide
5 Save the change and exit the menu.
The baud rate selection is stored in non-volatile memory, and does not change
when power has been off or after a remote interface reset.
Remote Interface: you can set or query the baud rate using the following
commands:
SYStem:COMMunicate:SERial
:BAUD <baud>
:BAUD?
Auto/Man
ENTER