Keithley 2450 User Manual

Model 2450
Interactive SourceMeter® Instrument Reference Manual Section 8:
TSP command reference
2450-901-01 Rev. B/September 2013 8-139
smu.source.offmode
This attribute defines the state of the source when the output is turned off.
Type TSP-Link accessible Affected by Where saved Default value
Attribute (RW) Yes
Restore configuration
Instrument reset
Power cycle
Source configuration list
Function change
Configuration script
Source configuration list
smu.OFFMODE_NORMAL
Usage
sourceOffMode = smu.source.offmode
smu.source.offmode = sourceOffMode
sourceOffMode
The output-off setting; set to one of the following values (see the Details below for
specifics regarding each option):
• smu.OFFMODE_NORMAL
• smu.OFFMODE_ZERO
• smu.OFFMODE_HIGHZ
•
smu.OFFMODE_GUARD
Details
Reading this attribute returns the output-off state of the source. Setting this attribute configures the output-off
state.
When the Model 2450 is set to the normal output-off state, the following settings are made when the source is
turned off:
• The measurement sense is set to 2-wire
• The voltage source is selected and set to 0 V
• The current limit is set to 10 percent of the full scale of the present current range
• OUTPUT OFF is displayed in the Home page Source area
• The Source button on the Home page shows the output that will be sourced when the output is turned
on again
When the high-impedance output-off state is selected and the output is turned off:
• The measurement sense is set to 2-wire
• The output relay opens, disconnecting the instrument as a load
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, when you turn off the output:
• The measurement sense is changed to 2-wire sense
• The source function is set to voltage
• The source voltage is set to 0
• Set the range to the presently selected range (turn off autorange)
• Program the voltage DAC to zero, and the current DAC to full scale of the present current range.
When the zero output-off state is selected, you can use the instrument as an ammeter because it is outputting
0 V.

Keithley 2450 Specifications

General

Brand	Keithley
Model	2450
Category	Test Equipment
Language	English