Memory:free[:All] - Keysight N1911A Programming Manual

MEMory:FREE[:ALL]?

This query returns the amount of memory free for sensor calibration tables (8480
Series sensors and N8480 Series sensors with Option CFT only), frequency
dependent offset tables, and save/recall registers. The format of the response is:
<bytes_available>,<bytes_in_use>
Syntax
Example
MEM:FREE?
N1911A/1912A P-Series Power Meters Programming Guide
:FREE
MEM
:ALL ?
This command queries the amount of free
memory in total.
MEMory Subsystem 7
281