Keithley 2461 Reference Manual

Section
2: General operation Model 2461 Interactive SourceMeter® Instrument
Reference Manual
2-130 2461-901-01 A/November 2015
Source readback
You can set the instrument to record and display the voltage or current of the configured source value
or the actual source value. When you use the configured source value, the instrument records and
displays the value that was configured. When you use the actual source value, the instrument
measures the actual source value immediately before making the measurement of the device under
test.
Using source readback results in more accurate measurements, at the cost of a reduction in
measurement speed.
When source readback is on, the front-panel display shows the measured source value and the buffer
records the measured source value immediately before the device under test measurement. For
example, if you have the source set to 60 V, you will see something like +059.998 V in the
SOURCE VOLTAGE area of the Home screen.
When source readback is off, the front-panel display shows the configured source value and the
buffer records the configured source value immediately before the measurement of the device under
test. For example, if the source is set to 60 V, you will see something like +060.000 V in the
SOURCE VOLTAGE area of the Home screen.
Setting source readback
Using the front panel:
1. Press the MENU key.
2. Under Source, select Settings.
3. Next to Source Readback, select On or Off.
4. Select HOME to return to the operating display.
Using a remote interface:
• SCPI commands: Refer to :SOURce[1]:<function>:READ:BACK (on page 6-99).
• TSP commands: Refer to smu.source.readback (on page 8-208).
Source delay
When you use the instrument to source and measure, there is a delay between when the source is
turned on and when the measurement is made. The delay provides a settling time for the source.
The amount of delay time depends on the settings that are made for the source delay. You can set a
manual value, or use the autodelay setting.
Figure 77: Model 2461 settling and delay times

Keithley 2461 Specifications

General

Maximum Current	7 A
Power	100 W
Resolution	6.5 digits
Source Measure Unit (SMU)	Yes
DC Voltage	100 V
Maximum Voltage	100 V
Display	5-inch capacitive touchscreen
Connectivity	USB, GPIB
Software	TSP
DC Current	7 A
Current Source Range	0 to 7 A
Voltage Measurement Range	100 mV to 100 V
Current Measurement Range	10 nA to 7 A
Voltage Measurement Resolution	100 nV