Keithley 2657A, Reference Manual, Page: 103 / 805

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 2: General operation
2657A-901-01 Rev. B/December 2012 2-79
Remote speed programming
Speed command
The following table summarizes commands to control speed. See TSP command reference (on page
7-1) for more information.
Speed commands*
Command Description
smua.measure.nplc = nplc
Sets the speed of the integrating ADC only (
nplc
can range from
0.001 to 25).
smua.measure.adc = adc Selects analog-to-digital converter (
adc =
smua.ADC_INTEGRATE
or
smua.ADC_FAST
).
* The speed setting is global and affects all measurement functions.
Speed programming example
Use the NPLC command to set the speed of the integrating analog-to-digital converter (ADC). The
programming example below illustrates how to set the speed to 10 PLC:
-- Set NPLC to 10.
smua.measure.nplc = 10
Sampling speed programming example
Use the measure interval to control the sampling speed of the fast ADC. The programming example
below illustrates how to configure the fast ADC to take 1000 measurements with 10
μ
s sampling
interval:
-- Select fast ADC.
smua.measure.adc = smua.ADC_FAST
-- Set measure count to 1000 readings.
smua.measure.count = 1000
-- Set sampling interval to 10 us (microseconds).
smua.measure.interval = 10e-6
Remote communication interfaces
You can choose from one of several communication interfaces to send commands to and receive
responses from the Model 2657A.
The Model 2657A can only be controlled from one communication interface at a time. The first
interface on which it receives a message takes control of the instrument. It ignores the other
interfaces until the instrument is returned to local operation.