RIGOL MSO/DS2000A Series - Manual (Page 242)

RIGOL Chapter 13 Signal Source
13-18 MSO2000A/DS2000A User’s Guide
“Store and Recall” to save the current waveform file in “.arb” format in the
internal memory (you can overwrite the original file or save the current
waveform again).
You can select the arbitrary waveforms in the internal or external memory for
output. For the details, refer to the introduction in “To Select Waveform”.