Keithley 2657A User Manual

Section 7: TSP command reference Model 2657A High Power System SourceMeter® Instrument Reference Manual
7-32 2657A-901-01 Rev. B/December 2012
Details
Assigning a value to this attribute sets the resolution for the timestamps. Reading this attribute returns the
timestamp resolution value. This value can only be changed with an empty buffer. Empty the buffer using the
bufferVar.clear() function.
The finest timestamp resolution is 0.000001 seconds (1 μs). At this resolution, the reading buffer can store
unique timestamps for up to 71 minutes. This value can be increased for very long tests.
The value specified when setting this attribute will be rounded to an even power of 2 μs.
For dedicated reading buffers, all buffer attributes are saved to nonvolatile memory only when the reading buffer
is saved to nonvolatile memory.
Example
smua.nvbuffer1.timestampresolution = 0.000008
Sets the timestamp resolution of
dedicated reading buffer 1 to 8 μs.
Also see
bufferVar.clear() (on page 7-19)
bufferVar.collecttimestamps
(on page 7-21)
bufferVar.timestamps
(on page 7-32)
Reading buffers
(on page 3-6)
smuX.measure.overlappedY()
(on page 7-204)
smuX.measure.Y()
(on page 7-208)
smuX.nvbufferY
(on page 7-210)
smuX.trigger.measure.Y()
(on page 7-238)
bufferVar.timestamps
When enabled by the bufferVar.collecttimestamps attribute, this attribute contains the timestamp (in
seconds) of when each reading saved in the specified reading buffer occurred.
Type TSP-Link accessible Affected by Where saved Default value
Attribute (R) Yes Clearing the buffer See Details Not applicable
Usage
timestamp = bufferVar.timestamps[N]
timestamp
The timestamp of reading number N in the specified buffer when the reading was
acquired
bufferVar
The reading buffer; can be a dynamically allocated user-defined buffer or a
dedicated reading buffer
N
The reading number (1 to bufferVar.n)
Details
The bufferVar.timestamps information from a reading buffer is only available if the
bufferVar.collecttimestamps attribute is set to 1 (default setting). If it is set to 0, you cannot access any
time information from a reading buffer.
If enabled, this buffer recall attribute is like an array (a Lua table) that contains timestamps, in seconds, of when
each reading occurred. These are relative to the bufferVar.basetimestamp for the buffer. See Reading
buffer commands (on page 3-11) for more information.
For dedicated reading buffers, all buffer attributes are saved to nonvolatile memory only when the reading buffer
is saved to nonvolatile memory.

Keithley 2657A Specifications

General

Brand	Keithley
Model	2657A
Category	Measuring Instruments
Language	English