Keithley SourceMeter 2600 Series Reference Manual page 186

6-10 Range, Digits, Speed, Rel, and Filters
Speed programming example
Use the NPLC command to set the speed. For example, send the following
parameter to set the speed to 10 PLC:
smua.reset()
smua.measure.nplc = 10
Rel
The rel (relative) feature can be used to null offsets or subtract a baseline reading
from present and future readings. With REL enabled, subsequent readings will be
the difference between the actual input value and the rel value as follows:
Displayed Reading = Actual Input - Rel Value
Once a rel value is established for a measurement function, the value is the same
for all ranges. For example, if 0.5A is set as a rel value on the 1A range, the rel
value is also 0.5A on the lower current ranges.
Selecting a range that cannot accommodate the rel value does not cause an
overflow condition, but it also does not increase the maximum allowable input for
that range. For example, on 1A range, the SourceMeter still overflows for a
>1.02A input.
Front panel rel
Enabling and disabling rel
Rel can be used to null out zero offsets or to establish a zero baseline by pressing
the REL key. The reading (which becomes the rel value) is subtracted from itself.
As a result, a zero reading is displayed. Pressing REL a second time disables rel.
Defining a rel value
A unique rel value can be established for the selected measurement function from
the front panel as follows:
1.
2.
2600S-901-01 Rev. A / May 2006
NOTE When rel is enabled, the REL annunciator turns on.
Changing measurement functions disables rel.
Press CONFIG then REL.
Choose the measurement function (CURRENT, VOLTAGE, OHMS, or
WATTS), then press ENTER or the Rotary Knob.
Return to
Series 2600 System SourceMeters Reference Manual
--Restore Series 2600 defaults.
--Set NPLC to 10.
Section 6 topics