MDO3000 Programmer Manual.pdf - 第438页

Commands Listed in A lphabetical Order MA TH[1]:DEFine This command speciﬁes the current math function as a text string. Y ou must also specify the type (dual waveform, FFT , advanced math, or spectrum math ) using MA TH…

Commands Listed in Alphabetical Order

MASK:USER:WID

TH?

might return 0.0E+0, which is the default.

MATH[1]? (Query Only)

Returns the deﬁnition of the math waveform. The returned data depends on the

setting of the MATH[1]:TYPe command.

Group

Math

Syntax

MATH[1]?

Related Commands

MATH[1]:TYPe

Examples

MATH? or MATH1 ? might return :MATH :TYPE DUAL;D EFINE

"CH1+CH2";VERTICAL:SCALE 100.0000E-3;POSITION

0.0000;UNITS "V";:MATH: 4.0000E-6;P OSITION 50.0 000;UNITS

"s";:MATH:SPECTRAL:MAG DB;WINDOW HA NNING

MATH[1]:AUTOSCale

Sets (or queries) the state of automatic vertical scaling of the math waveform. The

default state is ON (1).

Group

Math

Syntax

MATH[1]:AUTOSCale?

MATH[1]:AUTOSCale {0|1|OFF|ON}

Arguments

1 or ON enables automatic vertical scaling of the math waveform when the RF

reference level falls below -25.0 dBm. Reference levels greater than or equal

to -25.0 dBm cause the probe to go into

BYPass mode. The reference level is

set/queried using the command

RF:REFLevel.

0 or OFF disables math autoscaling.

Examples

MATH[1]:AUTOSC ON enables automatic vertical scaling of the math waveform.

MATHAUTOSCALE? might return 1 indicating that auto-scaling is enabled for the

math waveform.

MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-407

Commands Listed in Alphabetical Order

MATH[1]:DEFine

This command speciﬁes the current math function as a text string. You must

also specify the type (dual waveform, FFT, advanced math, or spectrum math)

using MATH[1]:TYPe

Dual math expressions are strings of the form

<wfm> <o peration> <wfm>,

where the <wfm>s are any combination of live analog or reference waveforms

in the time domain display, the <operation> is any of +, -, * or /, and the type

has been se

tto

DUAL.

FFT math expressions are strings of the form

FFT(<wfm>), where <wfm> is any

live anal

og or reference waveforms in the time domain display, and the type has

been set to

FFT.

NOTE. You can also use FFT as part of a math expression by setting the type

ADVanced

using MATH[1]:TYPe. See examples of advanced type math

expressions below.

Advanced math expressions extend beyond dual math expressions, incorporating

combinations of advanced math functions, measurements, and operators.

Spectrum math (MDO models) expressions are strings of the form

<wfm><operation><wfm>, where the waveforms are any combination of live RF

or reference traces in the frequency domain display, the <operation> is either +

or –, and type has been set to

SPECTRUM.

Group

Math

Syntax

MATH[1]:DEFine <QString>

MATH[1]:DEFine?

Related Commands

MATHVAR:VAR<x>,

MATH[1]:TYPe

Arguments

<QString> quoted string argument is the mathematical expression that deﬁnes

the waveform.

2-408 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual

Commands Listed in Alphabetical Order

Table 2-56: Mat

h expression elements

Element Description Example

CH1-CH4

REF1-REF4

Speciﬁes an an

alog channel or

reference waveform as the data source.

Referenced as <wfm> in the math

operators de

scriptions.

:MATH:DEFINE "FFT(C H1)"

Automatic m

easurements of waveforms

See also MEASUrement:IMMed:TYPe and MEASUrement:MEAS<x>:TYPe .

AMPlitude(<wfm>)

Thehighval

ue less the low value

measured over the entire waveform or

gated region.

:MATH:DEFI

"AMPlitude(CH1)"

AREa(<wfm>)

Area measurement is a voltage over

time measurement. It returns the area

over the en

tire waveform or gated region

in volt-seconds. Area m easured above

ground is positive; area measured

below gro

und is negative.

:MATH:DEFINE "AREA( CH1)"

BURst(<

wfm>)

Burst wi

dth: the duration of a burst

(a series of transient events) and is

measured over the entire waveform or

gated re

gion.

:MATH:DEFINE "BURST (CH1)"

CARea(

<wfm>)

Cycle a

rea: a voltage over time

measurement. The measurement is the

area over the ﬁrst cycle in the waveform

or the ﬁ

rst cycle in the gated region

expressed in volt-seconds. The area

above the common reference point

is pos

itive, and the area below the

common reference point is negative.

:MATH:DEFINE "CAREA (CH1)"

CMEan(<wfm>) Cycle mean: the arithmetic mean over

the ﬁrst c ycle in the w aveform or the

ﬁrst

cycle in the gated region.

:MATH:DEFINE "CMEAN (CH1)"

CRM

s(<wfm>)

Cyc

le RMS: the true Root Mean Square

voltage o ver the ﬁrst cycle in the

waveform or the ﬁrst cycle in the gated

reg

ion.

:MATH:DEFINE "CRMS( CH1)"

Lay(<wfm>,<wfm>)

e time between the mid reference

(default 50%) a mplitude point of two

different waveforms. See also P hase.

:MATH:DEFINE

ELAY(CH1,CH2)"

FA LL(<wfm>) The time required for the falling edge

ftheﬁrst pulse in the waveform

or gated region to fall from the high

reference value (default = 90%) to the

ow reference value (default = 10% ) of

the ﬁnal value.

:MATH:DEFINE "FALL( CH1)"

MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-409