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Section 7: Command reference
Model 2651A High Power System SourceMeter® Instrument Reference Manual
7-178
2651A-901-01 Rev. A / March 2011
Details
A new password can only be assigned when calibration has been unlocked.
The calibration password is write-only and cannot be read.
Example
smua.cal.password = "LetMeIn"
Assigns a new calibration password for SMU Channel A.
Also see
(on page 7-181)
(on page B-16)
smuX.cal.polarity
This attribute controls which calibration constants are used for all subsequent measurements.
Type
TSP-Link accessible
Affected by
Where saved
Default value
Attribute (RW)
Yes
Instrument reset
SMU reset
SMU cal. lock
Not saved
smuX.CAL_AUTO
Usage
calPolarity
= smu
X
.cal.polarity
smu
X
.cal.polarity =
calPolarity
calPolarity
The polarity to use for measurements. Set to one of the following values:
0
or
smu
X
.CAL_AUTO
: Automatic polarity detection
1
or
smu
X
.CAL_POSITIVE
: Measure with positive polarity calibration constants
2
or
smu
X
.CAL_NEGATIVE
: Measure with negative polarity calibration constants
X
SMU channel (for example,
smua.cal.polarity
applies to SMU channel A).
Details
This attribute controls which polarity calibration constants are used to make all subsequent measurements. This
attribute does not affect the
smu
X
.measure.calibrate
Y
()
or
smuX.source.calibrate
Y
()
commands.
The polarity for those commands are dictated by the range parameter given to the command. The measurement
calibration commands require the measurements provided to have been made using the polarity being
calibrated.
When making those measurements with calibration points far away from zero, the desired polarity constants are
inherently used. When measuring near zero, it is possible for the measurement to be made using the calibration
constants from either polarity without knowing which was used. Setting this attribute to positive or negative forces
measurements to be made using the calibration constants for a given polarity rather than basing the choice on
the raw measurement data.
This attribute can only be set to positive or negative when calibration is unlocked. This attribute will automatically
be set to
smu
X
.CAL_AUTO
when calibration is locked.
Example
smua.cal.polarity = smua.CAL_POSITIVE
Selects positive calibration constants for all
subsequent measurements on SMU channel A.