USING THE COMBISCOPE INSTRUMENTS 3 - 17
3.3.8 Fetching characteristics from memory traces
The FETCh? query not only allows you to determine a characteristic from the last
acquired waveform, it also allows you to calculate a signal characteristic from a
waveform that is stored in a trace memory element.
Example:
FETCh:RISE:TIME? (@M3_4) Calculates and returns the default rise time
from a waveform that is stored in trace memory
M3_4.
FETCh:PERiod? (@M4_1) Determines and returns the period of the
waveform that is stored in trace memory M4_1.
Notice that such a FETCh? query operates properly only when there is valid
waveform data stored in the trace memory.
PROGRAM EXAMPLE:
In this example the signal acquired via channel 2 is stored in memory register 1.
The AC-RMS, peak-to-peak, and amplitude values of the stored signal are
fetched and printed.
DIM response AS STRING
*
10
CALL Send(0, 8, "CONFigure:AC (@2)", 1) ’
CALL Send(0, 8, "SENSe:FUNCtion ’XTIMe:VOLTage2’", 1)’
CALL Send(0, 8, "INITiate", 1) ’
CALL Send(0, 8, "TRACe:COPY M1_2,CH2", 1) ’
’
’
Now trace area 2 of memory register 1 is filled with the channel 2 trace.
’
CALL Send(0, 8, "FETCh:AC? (@M1_2)", 1) ’
CALL Receive(0, 8, response$, 256) ’
PRINT "AC-RMS value : "; response$ ’
CALL Send(0, 8, "FETCh:PTPeak? (@M1_2)", 1) ’
Fetches Peak-To- Peak of M1_2
CALL Receive(0, 8, response$, 256) ’
Enters Peak-To-Peak value
PRINT "Peak-To-Peak value: "; response$ ’
Prints Peak_to_peak value
CALL Send(0, 8, "FETCh:AMPLitude? (@M1_2)", 1) ’
Fetches amplitude of M1_2
CALL Receive(0, 8, response$, 256) ’
PRINT "Amplitude value : "; response$ ’
