Smux.cal.polarity - Keithley 2651A Reference Manual

Section 7: Command reference
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"
Also see
smuX.cal.unlock()
Adjustment (on page B-16)

smuX.cal.polarity

This attribute controls which calibration constants are used for all subsequent measurements.
Type TSP-Link accessible
Attribute (RW) Yes
Usage
calPolarity = smuX.cal.polarity
smuX.cal.polarity = calPolarity
calPolarity
X
Details
This attribute controls which polarity calibration constants are used to make all subsequent measurements. This
attribute does not affect the smuX.measure.calibrateY() or smuX.source.calibrateY() 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 smuX.CAL_AUTO when calibration is locked.
Example
smua.cal.polarity = smua.CAL_POSITIVE
7-178
Model 2651A High Power System SourceMeter® Instrument Reference Manual
(on page 7-181)
Affected by
Instrument reset
SMU reset
SMU cal. lock
The polarity to use for measurements. Set to one of the following values:
0 or smuX.CAL_AUTO: Automatic polarity detection
1 or smuX.CAL_POSITIVE: Measure with positive polarity calibration constants
2 or smuX.CAL_NEGATIVE: Measure with negative polarity calibration constants
SMU channel (for example, smua.cal.polarity applies to SMU channel A).
Assigns a new calibration password for SMU Channel A.
Where saved Default value
Not saved smuX.CAL_AUTO
Selects positive calibration constants for all
subsequent measurements on SMU channel A.
2651A-901-01 Rev. A / March 2011