Section 8: TSP command reference
Model 2450 Interactive SourceMeter® Instrument Reference Manual
8-144
2450-901-01 Rev. B/September 2013
smu.source.readback
This attribute determines if the instrument records the measured source value or the configured source value
when making a measurement.
Type
TSP-Link accessible
Affected by
Where saved
Default value
Attribute (RW)
Yes
Restore configuration
Instrument reset
Power cycle
Source configuration list
Function change
Configuration script
Source configuration list
smu.ON
Usage
state
= smu.source.readback
smu.source.readback =
state
state
Disable read back:
smu.OFF
Enable read back:
smu.ON
Details
When you use the configured source value (source readback off), the instrument records and displays the value
that was configured. When you use the actual source value (source readback on), the instrument measures the
actual source value immediately before making the device under test measurement.
Using source readback results in more accurate measurements, but also 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. 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 device-under-test measurement.
Example
reset()
testDataBuffer = buffer.make(100)
smu.source.func = smu.FUNC_DC_VOLTAGE
smu.measure.func = smu.FUNC_DC_CURRENT
smu.source.readback = smu.ON
smu.source.level = 10
smu.measure.count = 100
smu.source.output = smu.ON
smu.measure.read(testDataBuffer)
smu.source.output = smu.OFF
printbuffer(1, 100, testDataBuffer.sourcevalues,
testDataBuffer)
Reset the instrument to default
settings.
Make a buffer named
testDataBuffer
that can hold 100
readings.
Set source function to voltage.
Set the measurement function to
current.
Set read back on.
Set the instrument to take 100
readings.
Turn the output on.
Take the measurements.
Turn the output off.
Get the source values and
measurements from the buffer.
Also see
(on page 8-103)
(on page 8-134)