Keithley 3700 series Reference Manual page 255

Series 3700 System Switch/Multimeter Reference Manual
dmm.rel.enable
Remarks
Also see
Example
dmm.rel.level
Attribute
Usage
Remarks
Also see
Document Number: 3700S-901-01 Rev. A / August 2007
This is the relative measurement control setting for the DMM and it applies to the
selected function as indicated by dmm.func. Querying the setting when the selected
function does not support it will cause nil to be returned.
When relative measurements are enabled, all subsequent measured readings will be
offset by the specified relative offset (see dmm.rel.level). Specifically, each returned
measured relative reading will be the result of the following calculation:
Relative reading = Actual measured reading – Relative offset value
The command will generate an error when dmm.func equals one of the following:

―continuity‖

―nofunction‖
Also, an error will be generated if the value is out of range for the selected function.
Changing functions with dmm.func has no effect on this setting.
The factory default and dmm.reset function value is dmm.OFF.
dmm.rel.level (on page 9-111)
To enable the relative measurements for AC current:
dmm.func = "accurrent"
dmm.rel.enable = dmm.ON
The offset value for relative measurements for the DMM.
To read the relative offset level:
value = dmm.rel.level
value: Represents the present relative offset level.
To write the relative offset level:
dmm.rel.level = value
value: Represents the desired relative offset level.
This is the relative offset level setting for the DMM. It applies to the selected function
as indicated by dmm.func. Querying the setting when the selected function does not
support it will cause nil to be returned.
When relative measurements are enabled (see dmm.rel.enable), all subsequent
measured readings will be offset by the specified relative offset value. Specifically,
each returned measured relative reading will be the result of the following calculation:
Relative reading = Actual measured reading – Relative offset value
The command will generate an error when dmm.func = ―continuity‖ or ―nofunction‖.
Also, an error will be generated if the value is out of range for the selected function.
Changing functions with dmm.func has no effect on this setting.
The factory default and dmm.reset function value is 0.
NOTE Using dmm.rel.level = dmm.measure() to set the REL level will include math,
limits and filter operations, if enabled.
dmm.rel.enable (on page 9-110)
Section 9: Instrument Control Library (ICL)
9-111