Keithley 2450 Reference Manual page 393

Section 6: SCPI command reference
Details
This command indicates the state of the range for the selected source. When automatic source range is
disabled, the source range is set manually.
When automatic source range is enabled, the instrument selects the range that is most appropriate for the value
that is being sourced. The output level controls the range. If you read the range after the output level is set, the
instrument returns the range that the instrument chose as appropriate for that source level.
If the source range is set to a specific value from the front panel or a remote command, the setting for automatic
range is set to disabled.
Example
SOUR:CURR:RANG:AUTO ON
Also see
:SOURce[1]:<function>:RANGe
6-76
Model 2450 Interactive SourceMeter® Instrument Reference Manual
(on page 6-74)
Enable the automatic source range.
2450-901-01 Rev. B/September 2013