Tektronix FCA3000 Series, Programmer'S Manual

Page: 71 / 191

Command Descriptions
When the instrument has made an array of measurements,
FETCh:ARRay?
10 fetches the fi rst 10 measuring results from the output queue. The second
FETCh:ARRay?
10 fetches the result 11 to 20, and so on. When the last measuring
result is fetched,
FETCh:ARRay?
starts over again with the fi rst result.
In totalizing for instance, you may want to read the last measurement result
instead of the
fi rst one. This is possible if you set the array size to a negative
number. Example:
FETCh:ARRay?
-5 fetches the last fi ve results. The output
queue pointer is not altered when the array size is negative. That is, the example
above always returns the last
fi ve results every time the command is sent.
FETCh:ARRay?
-1 is useful to fetch intermediate results in free-running or array
measurements without interrupting the measurement.
Group Fetch
Syntax
FETCh:ARRay? <fetch array size>|MAX
FETCh[:SCALar]? (Query Only)
The fetch query retrieves one measuring result from the measurement result buffer
of the instrument without making new measurements. Fetch does not work unless
a measurement was taken by the
INITiate , MEASure:<MeasuringFunction>? ,
or READ? commands.
If the instrument has made an array of measurements,
FETCh[:SCALar]?
fetches
the fi rst measuring results fi rst. The second
FETCh[:SCALar]?
fetches the
second result and so on. When the last measuring result is fetched, fetch starts
over again with the
fi rst result.
The same measuring result can be fetched again and again if the result is valid,
until the following occurs:
*RST is received.
an INITiate, MEASure or READ command is executed
any recon fi guration is done.
an acquisition of a new reading is started.
If the measuring result in the output buffer is invalid, but a new measurement was
started, the fetch query completes when a new measuring result becomes valid. If
no new measurement was started, an error is returned.
The optional SCALar means that one result is retrieved.
Group
Fetch
FCA3000, FCA3100, MCA3000 Series Programmer Manual 2-55