Keithley 2657A, Справочное руководство, Страница: 62 / 805

Section 2: General operation Model 2657A High Power System SourceMeter® Instrument Reference Manual
2-38 2657A-901-01 Rev. B/December 2012
Contact check commands
The following table summarizes the basic contact check commands. For a more complete description
of these commands, refer to the
TSP command reference (on page 7-1). For connection information,
refer to Contact check connections (on page 2-51).
Basic contact check commands
Command Description
flag = smua.contact.check() Determine if contact resistance is lower than threshold.
rhi, rlo = smua.contact.r() Measure the aggregate contact resistance.
smua.contact.speed = speed_opt
Set
speed_opt
to one of the following:
0
or
smua.CONTACT_FAST
1
or
smua.CONTACT_MEDIUM
2
or
smua.CONTACT_SLOW
smua.contact.threshold = rvalue Set resistance threshold for the contact check function.
Contact check programming example
The following programming example illustrates the setup and command sequence for a typical
contact measurement. These commands set the contact check speed to fast and the threshold to
100
Ω
. Then, a contact check measurement against the threshold is made. If it fails, a more accurate
contact check measurement is made, and the test is aborted. Otherwise, the output is turned on, and
the test continues.
-- Restore defaults.
smua.reset()
-- Set speed to fast.
smua.contact.speed = smua.CONTACT_FAST
-- Set threshold to 100 ohms.
smua.contact.threshold = 100
-- Check contacts against threshold.
if not smua.contact.check() then
-- Set speed to slow.
smua.contact.speed = smua.CONTACT_SLOW
-- Get aggregate resistance readings.
rhi, rlo = smua.contact.r()
-- Return contact resistances to the host.
print(rhi, rlo)
-- Terminate execution.
exit()
end
-- Turn output on and continue.
smua.source.output = smua.OUTPUT_ON
Saved setups
You can restore the Model 2657A to one of six nonvolatile memory setup configurations (five user
setups and one factory default), or to a setup stored on an external USB flash drive. As shipped from
the factory, the Model 2657A powers up with the factory default settings, which cannot be overwritten.
The default settings are also in the five user setup locations, but may be overwritten. The factory
default settings are listed in the command descriptions in the
TSP command reference (on page 7-1).
The setup configuration that is used when the instrument powers up can be changed.