MDO3000 Programmer Manual.pdf - 第1098页

Appendix D: W aveform T ransfer (WFMOutpre and CUR V e Query) Examples WFMOutpre? Q uery results Explanation PT_OFF 0 This is a query provided only for compatib ility with other T ektronix oscilloscopes. The returned val…

Appendix D: Waveform Transfer (WFMOutpre and CURVe Query) Examples

NOTE. You can al

so use the

WAVFrm?

query, which concatenates the

WFMOutpre?

and

CURVe?

queries.

WFMOutpre? Query results

Explanation

WFMOUTPRE:B

YT_NR 8

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 autom

atically changes the

BIT_NR value a ccordingly. (This value can also be set

using the DATa:WIDth command.)

BIT_NR 64

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 th

BYT_NR value accordingly.

ENCDG ASCII

This valu

e speciﬁes the encoding of the w aveform 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

WFMOutpr

e:ENCdg, WFMOutpre:BN_Fmt,

: and WFMOutpre:BYT_Or values

using a single command.)

BN_FMT R

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 ASCii encoding.

BYT_OR MSB

This va

lue speciﬁes the byte order for the BINARY encoding, which in this case 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, Digital

mode"

This quoted string represents information about the source waveform that would be returned

by a.

FMOutpre:WFId?

query. It cannot be changed.

NR_PT 25

This value indicates the number of data points in the waveform record. (If you w ould like to

determine only this v alue, use the WFMOutpre:NR_Pt? query.) Note: this value is typically

equal to the full record length, but you also have the option to transfer only a portion of the

record length by using the DATa: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 YT format. This is query only – the returned values can be Y for YT

format or ENV for envelope format (min/max pairs). (If you would like to determine only this

value, use the WFMOutpre:PT_Fmt? query.)

PT_ORDER LINEAR

This val u e 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. Typic ally, this value is “s”, representing seconds.

When using the math 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.)

XINCR 1.2121E-9

This value indicates the time, in seconds, or frequency, in hertz, between data points in the

waveform record. This is query only. (If you would like to determine only this value, use

the WFMOutpre:XINcr? query.)

XZER0 -6.0606E-6

This value indicates the time, in seconds, or frequency, in hertz, of the ﬁrst data point in the

waveform record. This time or frequency is relative to the time of the trigger, which is always

0. So, this XZEro time or frequency can be negative. This is query only. (If you would like to

determine only this value, use the WFMOutpre:XZEro? query.)

MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual D-13

Appendix D: Waveform Transfer (WFMOutpre and CURVe Query) Examples

WFMOutpre? Q uery results

Explanation

PT_OFF 0

This is a query provided only for compatibility with other Tektronix oscilloscopes. The

returned value is always 0. ( If you would like to determine only this value, use the

WFMOutpre:PT

_Off? query.)

YUNIT “State”

This value in

dicates the vertical units of data points in the waveform record. This can be

any of several string values, depending upon the vertical units of the source waveform –

in this case, State. T his is query only. (If you would like to determine only this value, use

the WFMOutp

re:YUNit? query.)

YMULT 1.0000

This value i

ndicates the multiplying factor to convert the data point values from digitizing

levels to the units speciﬁed by the

WFMOUTpre:YUNit command. This is query only. (If

you would like to determine only this value, use the WFMO utpre:YMUlt? query.)

YOFF 0.0E+0

This value indicates the vertical position of the source waveform in digitizing levels. There

are25dig

itizing levels per vertical division. This is query only. (If y ou would like to determine

only this v alue, use the WFMOutpre:YOFf? query.)

YZERO 0.0

E+0

This value indicates the vertical offset of the source waveform in units speciﬁed by the

WFMOUTpre:YUNit command. This is query only. (If you would like to determine only this

value, u

se the WFMOutpre:YZEro? query.)

Example 7: RF Frequency Domain Waveform

Goal: Transfer 5 points of RF frequency domain data from the oscilloscope to

a PC using 4 bytes per point.

NOTE. A frequency domain waveform used in data transfer from the oscilloscope

to a PC or other device may be one of the four RF frequency domain traces or

the S

pectrum Math waveform.

Command Comment

:DATa:SOUrce RF_NORMal

:DATa:STARt 495

:DATa:STOP 505

WFMOutpre:ENCdg ASCi i

:WFMOutpre:BYT_Nr 4

:HEADer 1

:VERBose 1

D-14 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual

Appendix D: Waveform Transfer (WFMOutpre and CURVe Query) Examples

Command Comment

:WFMOutpre?

Returns the following values. Each v alue represents the current settings that

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

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,

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

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