Keithley 2461 Reference Manual

Section
8: TSP command reference Model 2461 Interactive SourceMeter® Instrument Refer
ence Manual
8-164 2461-901-01 A/November 2015
smu.measure.nplc
This command sets the time that the input signal is measured for the selected function.
Type TSP-Link accessible Affected by Where saved Default value
Attribute (RW) Yes
Restore configuration
Instrument reset
Power cycle
Measure configuration list
Function change
Configuration script
Measure configuration list
1
Usage
nplc = smu.measure.nplc
smu.measure.nplc = nplc
nplc
The number of power line cycles: 0.01 to 10
Details
This command sets the amount of time that the input signal is measured.
The amount of time is specified as the number of power line cycles (NPLCs). Each PLC for 60 Hz is
16.67 ms (1/60) and each PLC for 50 Hz is 20 ms (1/50). For 60 Hz, if you set the NPLC to 0.1, the
measure time is 1.667 ms.
This command is set for the measurement of specific functions (current, resistance, or voltage).
The shortest amount of time results in the fastest reading rate, but increases the reading noise and
decreases the number of usable digits.
The longest amount of time provides the lowest reading noise and more usable digits, but has the
slowest reading rate.
Settings between the fastest and slowest number of PLCs are a compromise between speed and
noise.
If you change the PLCs, you may want to adjust the displayed digits to reflect the change in usable
digits.
Example
smu.measure.func = smu.FUNC_DC_VOLTAGE
smu.measure.nplc = 0.5
Sets the measurement time to 0.0083 (0.5/60)
seconds.
Also see
Using NPLCs to adjust speed and accuracy (on page 4-9)

Keithley 2461 Specifications

General

Brand	Keithley
Model	2461
Category	Measuring Instruments
Language	English