Keithley 2651A, Reference Manual

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Section 7: Command reference Model 2651A High Power System SourceMeter® Instrument Reference Manual
7-18 2651A-901-01 Rev. A / March 2011
Also see
smuX.measure.overlappedY() (on page 7-201)
smuX.measure.Y() (on page 7-205)
smuX.nvbufferY (on page 7-208)
smuX.trigger.measure.Y() (on page 7-238)
Reading buffers (on page 3-6)
bufferVar.cachemode
This attribute enables or disables the reading buffer cache (on or off).
Type TSP-Link accessible Affected by Where saved Default value
Attribute (RW) Yes Not applicable Not saved 1 (enabled)
Usage
cacheMode = bufferVar .cachemode
bufferVar .cachemode = cacheMode
cacheMode
The reading buffer cache mode; set to one of the following:
•
0
: Cache mode disabled (off)
•
1
: Cache mode enabled (on)
bufferVar
The reading buffer; can be a dynamically allocated buffer (user-defined), or a
dedicated reading buffer (such as
smua.nvbuffer1
)
Details
Assigning a value to this attribute enables or disables the reading buffer cache. When enabled, the reading buffer
cache improves access speed to reading buffer data.
If you run successive operations that overwrite reading buffer data, the reading buffer may return stale cache
data. This can happen when initiating successive sweeps without reconfiguring the sweep measurements or
when overwriting data in the reading buffer by setting the
bufferVar .fillmode
attribute to
smu X .FILL_WINDOW
. To avoid this, make sure to include commands that automatically invalidate the cache as
needed (for example, explicit calls to the
bufferVar .clearcache()
function) or disable the cache using this
attribute (
bufferVar .cachemode
).
Example
smua.nvbuffer1.cachemode = 1
Enables reading buffer cache of
dedicated reading buffer 1.
Also see
bufferVar.clearcache() (on page 7-20)
bufferVar.fillmode (on page 7-23)
bufferVar.capacity
This attribute contains the capacity of the buffer.
Type TSP-Link accessible Affected by Where saved Default value
Attribute (R) Yes Not applicable Not saved Not applicable