MDO3000 Programmer Manual.pdf - 第1100页

Appendix D: W aveform T ransfer (WFMOutpre and CUR V e Query) Examples XUNIT "Hz" This value indicates the units of the x-axis of the waveform record. This value is always “Hz” for RF frequency domain traces. T…

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Appendix D: Waveform Transfer (WFMOutpre and CURVe Query) Examples
Command Comment
:WFMOutpre?
Returns the following values. Each v alue represents the current settings that
a
CURVe? query will use to format the data that will be transferred from the
oscilloscope
to a P C or other device (see next table for explanations):
:WFMOUTPRE:BYT_NR 4;BIT_NR 32;ENCDG ASCII;BN_FMT
FP;BYT_OR MSB;WFID "RF_NORMAL, unknown coupling,
10.00W/div,
200.0MHz/div, 1001 points, Sa mple mode,
Center Freq: 2. 400GHz, Spa n: 2.000GHz, Refe rence
Level: 1.000mW";NR_PT 21 ;PT_FMT Y;P T_ORDER LIN EAR;XUNIT
"Hz";XINCR
2.0000E+6;XZERO 1. 4000E+9;PT_OFF 0;YUNIT
"W";YMULT 1.5625E-3;YOFF 0.0E+0;YZERO 0.0 E+0;DOMAIN
FREQUENCY;WFMTYPE RF_FD;CENTERFREQUENCY 2.4000E +9;SPAN
2.0000E+9
;REFLEVEL 1.0000E-3
:CURVe?
Returns th
e following values. Each value represents a data point:
:CURVE
2.43108E-10,1.62648E-10,2.78478E-10,4.15163 E-10,7.66223E-10,
7.63905E
-10,3.68375E-10,3.42668E-10,3.06422E-10,1.81 561E-10,
2.0223E-10,4.24327E-10,1.95298E-10,2.1304E- 10,9.41791E-11,
4.56513E-10,4.33067E-10,6.57215E-11,1.65388 E-10,9.09116E-10,
5.39507
E-10
WFMOutp
re? Query results
Explanation
BYT_NR 4
This val
ue specifies the number of bytes per data point in the waveform data. This value
is fixed for RF frequency domain traces.
BIT_NR
32
This value speci fi es the number of bits per data point in the waveform data. This value
is fixed for RF frequency domain traces.
ENCDG ASCII This value speci fies the encoding of the waveform data. To change this value (the other
possi
bility for RF frequency domain traces is FPBINARY), use the WFMOutpre:ENCdg
command. This value can also be set using the DATa:ENCdg command.
BN_F
MT FP
This value specifies the binary format, which in this case is FP (floating point). This value is
fixed for RF frequency domain traces. Note: This fi eld is not applicable for ASCii encoding.
BYT_OR MSB This value specifies the byte order for the BINARY encoding, which in this case is MSB
(mo
st 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 "RF_NORMAL, unknown
coupling, 10.00W/div, 200.0MHz/div,
10
01 points, Sample mode, Center
Freq: 2.400GHz, Span: 2.000GHz,
Reference Level: 1.000mW"
This quoted string represents information about the source waveform that would be returned
by a WFMOutpre:WFId? Query. It cannot be changed.
NR_PT 21
This value indicates the number of data points in the waveform record. (If you w ould like to
d
etermine only this value, use the WFMOutpre:NR_Pt? query.) Note: This value is typically
equal to the full record length of the RF frequency domain trace, but you also have the option
to transfer only a portion of the record using the DATs:STARt and DATa:STOP commands.
PT_FMT Y
This value indicates the format of the data points in the waveform record. In this case, the
value represents YF (Amplitude vs. Frequency) format. This is query only. (If you would like
to determine only this value, use the WFMOutpre:PT_Fmt? query.
PT_ORDER LINEAR .
This value is always LINear
MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual D-15
Appendix D: Waveform Transfer (WFMOutpre and CURVe Query) Examples
XUNIT "Hz"
This value indicates the units of the x-axis of the waveform record. This value is always “Hz”
for RF frequency domain traces. This is query onl y. (If you would like to determine only this
value, use the
WFMOutpre:XUNit? query.)
XINCR 2.0000
E+6
This value in
dicates the frequency, in hertz, between data points i n the waveform record.
This is query only. (If you would like to determine only this value, use the WFMOutpre:XINcr?
query.)
XZERO 1.4000E+9 This value indicates the frequency, in hertz, of the first data point in the waveform record.
This freque
ncy is relative to the time of the trigger, which is always 0. This XZEro frequency
can be negative. This is query only. (If you would like to determine only this value, use
the WFMOutpre:XZEro? query.)
PT_OFF 0 This is a query provided only for compatibility with other Tektronix oscilloscopes. T he
returned
valueisalways0. (Ifyouwouldliketo determine only this value, use the
WFMOutpre:PT_Off? query.)
YUNIT "W"
This value indicates the units of data points in the waveform record. T his value depends on
the vertical units of the source waveform – in this case, watts. This is query only. (If you
would li
ke to determine only this value, use the WFMOutpre:YUNit? query.)
YMULT 1.5625E-3
This val
ue indicates the multiplying factor to convert the data point values to the units
specified by the:WFMOutpre:YUNit command. This is query only. (If you would like to
determine only this value, use the WFMOutpre:YMUlt? query.)
YOFF 0.0E+0 This value indicates the vertical position of the source waveform. This value is unused for
RF fre
quency domain traces and is always 0.
YZERO
0.0E+0
This v
alue indicates the vertical offset of the source waveform. This value is unused for RF
frequency domain traces and is always 0.
DOMAIN FRE QUENCY This value indicates the domain i n w hich the source waveform is displayed and stored. For
RF time domain traces, the domain is Time and waveform transfer information is treated
as in
teger information. For RF frequency domain traces, the domain is Frequency and
waveform transfer information is treated as floating point information. This is query only. (If
you would like to determine only this value, use the WFMOutpre:DOMain? query.)
WFMTYPE RF_FD
This value indicates the type of the source waveform. RF_FD indicates an RF frequency
dom
ain trace (frequency domain waveform). This is query only. (If you would like to
determine only this value, use the WFMOutpre:WFMTYPe? query.)
CENTERFREQUENCY 2.4000E+9 T his value indicates the center frequency, in hertz, of the source waveform. This is query only.
(If you would like to determine only this value, use the WFMOutpre:CENTERFREQuency?
qu
ery.)
S
PAN 2.0000E+9
T
his value indicates the frequency span, in hertz, of the source waveform. This is query
only. (If you would like to determine only this value, use the WFMOutpre:SPAN? query.)
R
EFLEVEL 1.0000E-3
This value indicates the reference level, in watts, of the source waveform. This is query only.
(If you would like to determine only this value, use the WFMOutpre:REFLEvel? query.)
D-16 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual
Appendix E: Mask/Limit Command Sequence Examples
This section provides some sample mask command sequences that show you
how to accomplish a few typical tasks.
Example 1: Creating custom masks
Goal: Create a custom mask, run a test that stops on violation, and determine
the number
of hits per mask segment.
Command Comment
*RST Re sets the oscilloscope to the factory default settings.
:MASK:CUSTOM INIT This should display a triangle mask with one segm ent using the default horizontal
and verti
cal scope settings. (Note: the default horizontal scale is 4 µsec/div.)
You can v
erify that it’s a custom m ask by querying:
MASK:S
TANDARD?
Should
return CUSTOM .
Next, u
se mask commands to specify the mask parameters:
:MASK
:USER:AMPLitude 100.0000E-3
:MASK:USER:VSCALe 100.0000E-3
:MASK:USER:VPOS 0.0E+0
:MAS
K:USER:VOFFSet 0.0E+0
:MASK:USER:HSCALE 4.0000E-6
:MASK:USER:HTRIGPOS 500.0000E-3
:MAS
K:USER:WIDth 4.0000E-6
:MASK:USER:RECOrdlength 10000
:MASK:USER:TRIGTOSAMP 0.0E+0
Next, substitute a customized mask for the initial mask by creating two blue bands
ac
ross the screen, one above and one below the x-axis.
Note the dimensions of the display are 40e-6 X 10e-3 (10*horizontal_scale X
10*vertical_scale). The num ber of horizontal divisions is 10.
Th
e points in these lists are presented in a c ounter clock-wise manner starting with
the lower # left hand corner (-20e-6, .1) for SEG1 and (-20e-6,-.2) for SEG2:
:MASK:USER:SEG1:POINTS
-20e-6,.1,20e-6,.1,20e-6,.2,-20e-6,.2
:
MASK:USER:SEG2:POINTS
-20e-6,-.2,20e-6,-.2,20e-6,-.1,-20e-6,-.1
Next, force a failure. Generate 100KHz sine wave, amplitude 0.22 volt, offset 0.0.
:ACQUIRE:STATE? Should r eturn 1, indicating that acquisitions are taking place.
:MASK:STOPONVIOLATION ON This command will cause w aveform acquisitions to stop upon the first occurrence of a
waveform violation once the test starts.
:MASK:TEST:STATE ON Starts the test.
:ACQUIRE:STATE? Should now return 0, verifying that waveform acquisitions have stopped.
MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual E-1