WILLTEK 4400 Mobile Phone Tester Series, Руководство пользователя

Страница: 385 / 834

Chapter 8 SCPI
The Measurement subsystems
4460 GSM System Option and 4468 EDGE System Option Version 12.20
361
The FETCh subsystem
The FETCh subsystem enables you to read out the currently valid measurement
result value(s) of a measurement.
Important notes
– Before a measurement value may be read out with commands of the FETCh
subsystem, a MEASure command has to be issued first.
– After a continuous measurement has been started, the latest measurement
result value can be obtained using the related
:FETCh
command.
– In case an array measurement has been started, the related
:FETCh
command will return the entire measurement result array.
– If there are no measurement results to be read out by a
FETCh
command for
any reason, a timeout will occur. The wait time until a timeout occurs is
dependent on the type of measurement to be performed (see below).
– If the preceding
MEASure
command and the
FETCh
command do not
match, a timeout will occur.
– When you use the query form of any
MEASure
command, all measurement
results obtained will be handed back and the internal result register will be
cleared afterwards. Consequently, a subsequent
FETCh
command will lead
to a timeout (as above).
– The following timeouts have been implemented:
– 5 s for all RFTX measurements
– 30 s for all RFRX measurements
– 10 s for all RFSPectrum measurements
– 10 s for all AF measurements
There are two versions of a FETCh command:
– The
:FETCh:LAST?
command will read out the latest result of the last
MEASurement command issued - whatever command that was.
Using this command, please keep in mind that your control program then
has to take care of the number and format of the measurement result values
returned.
– The
:FETCH:{measProp};
commands will read out the latest result of
the measurement specified with
{measProp}
.
FETCh:LAST The
:FETCh:LAST?
command will read out the latest result of the last
MEASurement command issued - whatever command that was.
Using this command, please keep in mind that your control program then has to
take care of the number and format of the measurement result values returned.
To convert a result string back into single measurement result values, please refer
to section
“How to convert a result string back into numeric variables” on
page 356 .