When Should I Change The Output Off State; How Do I Make Contact Check Measurements - Keithley 2651A Reference Manual

Model 2651A High Power System SourceMeter® Instrument Reference Manual Section 9: Frequently asked questions (FAQs)

When should I change the output off state?

Carefully consider and configure the appropriate output-off state, source, and compliance levels
before connecting the Model 2651A High Power System SourceMeter
can deliver energy such as other voltage sources, batteries, capacitors, solar cells, or other System
SourceMeter instruments. Program recommended instrument settings before making connections to
the device. Failure to consider the output-off state, source, and compliance levels may result in
damage to the instrument or to the device under test.
The Model 2651A provides multiple output-off states. The multiple states are required because
different types of connected devices (or loads) require different behaviors from the High Power
System SourceMeter
as a diode is untroubled by a 0 V source connected across its terminals when the output is turned off.
However, connecting a 0 V source to the terminals of a battery causes the battery to discharge.
Therefore, thoughtful selection of the proper output-off state is important in order to prevent damage
to devices and instruments. This is especially true when the device can deliver energy to the Model
2651A, such as a battery, capacitor, or when another SourceMeter instrument is connected across
the output terminals. In these cases, you want to use an output-off state that isolates the instrument
from the device, either setting smuX.source.offfunc = smuX.OUTPUT_DCAMPS, or
smuX.source.offfunc = smuX.OUTPUT_DCVOLTS, as applicable. There are other guidelines to
follow when connecting the output of multiple Model 2651A instruments together to obtain a larger
current or voltage. Please refer to following references for more information:
•
Refer to
•
User's Manual section "Combining SMUs"
•
Keithley application notes on the

How do I make contact check measurements?

For information on making contact check measurements, see
2-37) and Contact check
2651A-901-01 Rev. A / March 2011
®
Instrument when its output is turned off. For instance, a passive device such
Combining SMU outputs
(on page 4-16).
CAUTION
(on page 2-48)
Keithley Instruments website
®
Instrument to a device that
(http://www.keithley.com)
Contact check measurements (on page
9-5