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Section 7: TSP command reference
Model 2657A High Power System SourceMeter® Instrument Reference Manual
7-196
2657A-901-01 Rev. B/December 2012
Remember that disabling automatic reference measurements may allow the instrument to gradually drift out of
specification. To minimize the drift, a reference and zero measurement should be made just before any critical
test sequences. You can use the
smu
X
.AUTOZERO_ONCE
setting to force a refresh of the reference and zero
measurements that are used for the present aperture setting.
The Model 2657A stores the reference measurements for the last ten NPLC settings that were used in a
reference cache. If an NPLC setting is selected and an entry for it is not in the cache, the oldest (least recently
used) entry is discarded to make room for the new entry.
The fast ADC (analog-to-digital converter) does not use the reference measurements associated with this
attribute. When this attribute is set to
smu
X
.AUTOZERO_AUTO
, the fast ADC does not acquire these reference
measurements. However, if the fast ADC is selected and you set this attribute to
smu
X
.AUTOZERO_ONCE
, the
integrating ADC will acquire a new set of reference measurements that will be used when the integrating ADC is
selected.
Example
smua.measure.autozero = 1
Performs autozero once for SMU channel A. Alternatively,
the value 1 may be replaced with
smua.AUTOZERO_ONCE
.
Also see
(on page 7-203)
(on page 7-211)
smuX.measure.calibrateY()
This function generates and activates new measurement calibration constants.
Type
TSP-Link accessible
Affected by
Where saved
Default value
Function
Yes
Usage
smu
X
.measure.calibrate
Y
(
range
,
cp1Measured
,
cp1Reference
,
cp2Measured
,
cp2Reference
)
X
Source-measure unit (SMU) channel (for example,
smua.measure.calibratev()
applies to SMU channel A)
Y
SMU measurement function (
v
= voltage,
i
= current)
range
The measurement range to calibrate
cp1Measured
The value measured by this SMU for calibration point 1
cp1Reference
The reference measurement for calibration point 1 as measured externally
cp2Measured
The value measured by this SMU for calibration point 2
cp2Reference
The reference measurement for calibration point 2 as measured externally
Содержание 2657A
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