MDO3000 Programmer Manual.pdf - 第1086页

Appendix D: W aveform T ransfer (WFMOutpre and CUR V e Query) Examples WFMOutpre? Query results Explanation BYT_NR 1 This value speci ﬁ es the number of bytes per data point in the waveform data. T o change this value au…

Appendix D: Waveform Transfer (WFMOutpre and CURVe

Query) Examples

Here are several examples of command sequences using the WFMOut pre? and

CURVe? queries to transfer data from the oscilloscope to a PC, with different data

sources, including Analog, Digital, Digital Collection, and RF frequencydomain

waveforms. Each command sequence example is followed by an explanation of

the return

WFMOutpre? results. The WFMOutpre? values act as settings that

apply to the

CURVe query data being transferred.

NOTE. In order to guarantee that the waveform data returned from

CURVE?

queries of multiple waveforms are correlated to the same acquisition, you

should use single sequence acquisition mode to acquire the waveform data

from a single acquisition. Single sequence acquisition mode is enabled using

ACQuire

:STOPAfter

SEQuence

Example 1: Analog Waveform (Channels 1–4)

Goal: Transfer 10,000 points of analog channel waveform data from the

oscilloscope to a PC.

Command Comment

:DATa:SOUrce CH1

:DATa:START 1

:DATa:STOP 10000

:WFMOutpre:ENCdg BI NARY

FMOutpre:BYT_Nr 1

:HEADer 1

: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 PC or other devic e (see next table for explanations):

:WFMOUTPRE:BYT_NR 1;BIT_NR 8;ENCDG BINARY;BN_FMT

RI;BYT_OR MSB;WFID "Ch1, DC coupling, 100 .0mV/div,

4.000us/div, 10000 points, Sample mode";NR_PT

10000;PT_FMT Y;PT_ ORDER LINEA R;XUNIT "s"; XINCR

4.0000E-9;XZERO -2 0.0000E-6;PT_OFF 0;YUNI T "V";YMULT

4.0000E-3;YOFF 0.0 E+0;YZERO 0 .0E+0

:CURVE?

Returns 10,000 data points:

:CURVe #510000<10,000 binary bytes of waveform data.>

NOTE. You can also use the

WAVFrm?

query, which concatenates the

WFMOutpre?

and

CURVe?

queries.

MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual D-1

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

WFMOutpre? Query results

Explanation

BYT_NR 1

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 automat

ically changes the

BIT_NR value accordingly. (Thisvaluecanalsobeset

using the DATa:WIDth command.)

BIT_NR 8

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 BINARY

This value s

peciﬁes the encoding of the waveform data. To change this value (the other

possibility is ASCii), 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,

WFMOutpre

:BN_Fmt,

: and WFMOutpre:BYT_Or values using a s ingle c ommand.)

BN_FMT RI

This valu

especiﬁes 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 value spec iﬁes the byte order for the BINARY encoding, which in this case is M SB

(most si

gniﬁcant byte ﬁrst). To change this value to LSB, use the WFMOutpre:BYT_Or

command. Note: this ﬁeld is not applicable for ASCii encoding.

WFID "Ch1, DC

coupling, 100.0mV/div,

4.000us/div, 10000

points, Sample mode"

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

by a.

WFMOutpre:WFId? query.

NR_PT 10000

This value indicates the number of data points in the waveform record to be transferred

using the CURVE? query. (If you would like to determine only this value, use the

WFMOutpre:NR_Pt? query.) N ote: this value i s 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 i ndicates 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 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. Typically, 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 WFMO utpre:XUNit? query.)

XINCR 4.0000E-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 -20.0000E-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.)

PT_OFF 0

This is a query provided only for compatibility w ith performance oscilloscopes. The

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

WFMOutpre:PT_Off? query.)

D-2 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual

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

WFMOutpre? Query results

Explanation

YUNIT “V”

This value indicates 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, v

olts. This is query only. (If y ou would like to determine only this value, use

the WFMOutpre:YUNit? query.)

YMULT 4.0000

E-3

This value indicates the multiplying factor to convert the data point values from digitizing

levels to the units s peciﬁed by the

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

youwouldli

ke to determine only this value, use the WFMOutpre:YMUlt? query.)

YOFF 0.0E+0

This value i

ndicates the vertical position of the source waveform in digitizing levels. There

are 25 digitizing l evels per vertical division. This is query only. (If you would like to determine

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

YZERO 0.0E+0

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

WFMOUTpr

e:YUNit

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

value, use the WFMOutpre:YZEro? query.)

Example

2: Digital Waveform (Channels DO-D15)

Goal: Transfer 25 points of digital channel waveform data from the oscilloscope

to a PC.

Command Comment

:DATa:SOUrce D5

:DATa:START 1

:DATa:STOP 25

:WFMOutpre:ENCdg AS Cii

:WFMOutpre:BYT_Nr 1

:HE

ADer 1

:VERBose 1

:WFMOutpre?

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

URVe?

query will use to format the data that will be transferred from the

oscilloscope to a PC or other devic e (see next table for explanations):

:WFMOUTPRE:BYT_NR 1;BIT_NR 8;ENCDG ASCII;BN_FMT

I;BYT_OR MSB;WFID "D5, u nknown coup ling,

100.0us/div, 10000 points, Digital mode";NR_PT 25;PT_FMT

Y;PT_ORDER LINEAR;XUNIT "s";XINCR 100.0000E-9;XZERO

500.0000E-6;PT_OFF 0 ;YUNIT "Sta te";YMULT 1 .0000;YOFF

0.0E+0;YZERO 0.0E+0

:CURVe?

Returns the following values. Each value represents a data point:

:CURVe 0,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0