Rigol DG4000 Series - Page 240

Explanation
You can send the :PA:OFFSet:[STATe] command to turn on or off the output offset
at the output terminal of the PA.
Return Format
The query returns the value of the output offset in scientific notation with 7
significant bits. For example, 1.234500E+00 which denotes the value
of the output offset is 1.2345V.