High Voltage SourceMeter Instrument Reference Manual Section 14:
2470-901-01 Rev. A / May 2019 14-163
Opening the relay disconnects external circuitry from the inputs and outputs of the instrument. To
prevent excessive wear on the output relay, do not use this output-off state for tests that turn the
output off and on frequently.
The high-impedance output-off state should be used when the instrument is connected to a power
source or another source-measure instrument. In some cases, it may also be appropriate for devices
such as capacitors.
When the zero output-off state is selected and you turn off the output:
• The measurement sense is changed to 2-wire
• The voltage source is selected and set to 0
• The range is set to the presently selected range (turn off autorange)
• If the source is voltage, the current limit is not changed
• If the source is current, the current limit is set to the programmed source current value or to 10%
full scale of the present current range, whichever is greater
When the zero output-off state is selected, you can use the instrument as an ammeter because it is
outputting 0 V.
When the guard output-off state is selected and the output is turned off, the following actions occur:
• The measurement sense is changed to 2-wire
• The current source is selected and set to 0 A if the source is set to current (amps); otherwise, the
out
put remains a voltage source when the output is turned off
• The voltage limit is set to 10% full scale of the present voltage range
Note that the front-panel display does not reflect all of the changes. For example, the 4-wire display
indicator continues to display when the output is off, even though the sense is changed to 2-wire.
Example
smu.source.offmode = smu.OFFMODE_HIGHZ
Sets the output-off state so that the
instrument opens the output relay when the
Also see
Output-off state (on page 4-16)
smu.source.output (on page 14-164)