Keithley 4200A-SCS, Reference Manual

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Section 13: LPT library function reference Model 4200A-SCS Parameter Analyzer Reference Manual
13-88 4200A-901-01 Rev. C / February 2017
sweepX
This command generates a ramp consisting of ascending or descending voltages or currents. The sweep consists
of a sequence of steps, each with a user-specified duration.
Usage
int sweepi(int instr_id , double startval , double endval , long stepno , double
step_delay );
int sweepv(int instr_id , double startval , double endval , long stepno , double
step_delay );
instr_id The instrument identification code of the sourcing instrument
startval The initial voltage or current level output from the sourcing instrument, which is
applied for the first sweep measurement; this value can be positive or negative
endval The final voltage or current level applied in the last step of the sweep; this value can
be positive or negative
stepno
The number of current or voltage changes in the sweep; the actual number of
forced data points is one greater than the number of steps specified
step_delay The delay in seconds between each step and the measurements defined by the
active measure list
Details
The
sweep X
command is always used with the
smeas X
,
sintg X
,
savg X
, or
rtfary
command.
The
sweep X
command causes a sourcing instrument to generate a series of ascending or
descending voltages or current changes called steps. During this source time, a measurement scan is
done at each step.
The actual number of forced data points is one more than the number of steps specified. This means
that the number of measurements made is the number of steps specified plus one. This is important
when dimensioning the size of the results array. Failure to make sure the array is big enough will
produce operating system access violation errors.
Measurements are stored in a one-dimensional array in the order they were made.
The
trig X g
,
trig X l
, and
trigcomp
commands can be used with the
sweep X
command, even
though they are also used with the
smeas X
,
sintg X
, or
savg X
commands. In this case, data
resulting from each of the steps is stored in an array, as noted above. However, once a trigger point
(for example, a level of current or voltage) is reached, the sourcing device stops incrementing or
decrementing and is held at a steady output level for the remainder of the sweep.
The system maintains a measurement scan table consisting of devices to measure. This table is
maintained by calls to the
smeas X
,
sintg X
,
savg X
, or
clrscn
command. As multiple calls to these
commands are made, the commands are appended to this table.