Measurement Control CMU
1100.4903.12 5.36 E-8
<Start> Start of current range (time or frequency or channel number).
<Samples> Number of samples in current range.
The subranges may overlap but must be within the total range of the
<meas_obj>. Test points outside this range are not measured (result NAN) and
do not enter into the ARIThmetical, MINimum and MAXimum values.
By default, only one range corresponding to the total measurement range is
used and all measurement values are returned.
Subarray results
Subarray results are retrieved by means of FETCh, SAMPle or READ queries,
with :SUBarrays inserted as a second-level keyword:
FETCh:SUBarrays<type>:<meas_obj>[:RESult]<spec>?
SAMPle:SUBarrays<type>:<meas_obj>[:RESult]<spec>?
READ:SUBarrays<type>:<meas_obj>[:RESult]<spec>?
In the default subarray configuration, these commands are identical with the
FETCh, SAMPle or READ queries described above (i.e. all measurement
results are read out).
FETCh command
FETCh<type>:<meas_obj>[:RESult]<spec>?
Retrieves the latest valid measurement results.
If the FETCh query is used immediately after an INITialize... command,
the first evaluation period is terminated before the query is executed so that a
valid result can be acquired. If called up repeatedly after termination of the first
evaluation period, the FETCh query may return the same results several times
until they have been updated after the next period.
A FETCh returns the results without interaction with the measurement (unsyn-
chronized query). In some cases this may cause inconsistent results to be read
so that the SAMPle command should be used while the measurement is in the
RUN state.
Measurement states According to the definition given above the effect of the FETCh query depends
on the measurement status and the history of the measurement:
Status Valid Results? Effect of FETCh...?
≠ OFF
Yes Returns the current results.
OFF No Generates an SCPI error –230, Data corrupt or stale. This is
why FETCh should not be used while the measurement is in the
OFF state.
RUN No Waits until valid results are available and returns these results.
STOP No Generates an SCPI error –230, Data corrupt or stale.
This scenario occurs, e.g. if the measurement is stopped ex-
plicitly before the first evaluation period has been terminated.
SAMPle command
SAMPle<type>:<meas_obj>[:RESult]<spec>?
Retrieves the results of the current evaluation period. In single shot measure-
ments, SAMPle is equivalent to READ.
In a continuous measurement, or in counting mode (see repetition mode in
Table 5-7), SAMPle is executed only after termination of the current evaluation
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