Keysight 34420A - Page 218

4 Remote Interface Reference
214 Keysight 34420A User’s Guide
The language 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 the programming language using the following
commands:
SYStem:LANGuage {SCPI | 181}
L1X (SCPI)
L2X (Keithley 181)