Appendix D: Waveform Transfer (WFMOutpre and CURVe Query) Examples
NOTE. The retur
ned hexadecimal data values for the Digital Collection are
formatted without leading zeroes. For example, a 4-byte d igital collection value
of FB386 should be interpreted as 000FB386.
NOTE. You can also use the
WAVFrm?
query, which concatenates the
WFMOutpre?
and
CURVe?
queries.
WFMOutpre? Q uery results
Explanation
WFMOUTPRE:BYT_NR 4
This value specifies the number of bytes per data point in the waveform data. To change
this value automatically, use the WFMOutpre:BYT_Nr command. Note that changing this
value automatically changes the
BIT_NR value accordingly. (This value can also be set
using the DATa:WIDth command.)
BIT_NR 32
This value specifies the number of bits per data point in the waveform data. To change this
value, use the WFMOutpre:BIT_Nr command. Note that changing this value automatically
changes the
BYT_NR value accordingly.
ENCDG ASCII
This value s peci fies the encoding of the waveform data. To change this value (the
other possibility is BINARY), use the WFMOutpre:ENCdg command. (This value can
also be set using the DATa:ENCdg command, which provides the ability to set the
WFMOutpre:ENCdg, WFMOut pre:BN_Fmt,: and WFMOut pre:BYT_Or values
using a single command.)
BN_FMT RI
This value specifies the binary format, which in this case is RI (signed integer). To change
this value (the other possibility is RP or positive integer), use the WFMOutpre:BN_Fmt
command. Note: this field is not applicable for AS Cii encoding.
BYT_OR MSB
This value specifies the byte order for the BINARY encoding, which in this c ase is MSB
(most significant byte first, also known as IBM format). To change this value to LSB, use the
WFMOutpre:BYT_Or command. Note: this field is not applicable for ASCii encoding.
WFID
"Digital, unknown
coupling, 100.0us/div,
10000 points, Digi tal
mod
e"
This quoted string represents information about the source waveform that would be returned
by a.
WFMOutpre:WFId? query. It cannot be changed.
NR_PT 25
Th
is value indicates the number of data points in the waveform record to be transferred
using the CURVE? query. (If y ou would like to determine only this v alue, use the
WFMOutpre:NR_Pt? query.) Note: this value is typically equal to the full record length,
bu
t you also have the option to transfer only a portion of the record length by using the
DATa:STARt and DATa:STOP commands.
P
T_FMT Y
This value indicates the format of the data points in the waveform record. In this case,
the value represents YT format. This is query only – the returned values can be Y for YT
f
ormat or ENV for envelope format (min/max pairs). (If y ou would like to determine only this
value, use the WFMOutpre:PT_Fmt? query.)
PT_ORDER LINEAR
This value is always LINear.
XUNIT “s”
This value indicates the units of the x-axis of the waveform record. This is determined by the
horizontal settings for the waveform source. For live channels, this value is “s”, representing
seconds. When using the m ath waveform as a source, the value can be “s” or “Hz”. This
is query only. (If you would like to determine only this value, use the WFMOutpre:XUNit?
query.)
D-6 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual
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