MDO3000 Programmer Manual.pdf - 第35页

Command Syntax If the header is off: FULL;1 1. Set commands and queries may be concatenated in the same messa ge. For example, ACQuire:MODe SAMple;NUM AVg ?;STATE? is a valid message that sets the acqu isition mode to sa…

Command Syntax

Abbreviating

You can abbrevi

ate many oscilloscope commands. Each command in this

documentation shows the minimum acceptable abbreviations in capitals. For

example, you can enter the command

ACQuire:NUMAvg simply as ACQ:NUMA

or acq:numa.

Abbreviation rules may change over time as new oscilloscope models are

introduced. Thus, for the most robust code, use the full spelling.

If you use the HEADer command to have command headers included as part

of query responses, you can further control whether the returned headers are

abbreviated or are full-length with the

VERBose command.

Concatenating

You can concatenate any combination of set commands and queries using a

semicolon (;). The oscilloscope executes concatenated commands in the order

received.

When concatenating commands and queries, you must follow these rules:

1. Separate completely different headers by a semicolon and by the beginning

colon on all commands except the ﬁrst one. For example, the commands

TRIGger:MODe NORMal and ACQuire:N UMAVg 8, can be concatenated

into the following single command:

TRIGger:MODe NORMal;:A CQuire:NUMAVg 8

2. If concatenated commands have headers that differ by only the last mnemonic,

you can abbreviate the second command and eliminate the beginning colon.

For example, you can concatenate the commands

ACQuire:MODe ENVelope

and ACQuir e:NUMAVg 8 into a single command:

ACQuire:MODe ENVelope; NUMAVg 8

The longer version works equally well:

ACQuire:MODe ENVelope; :ACQuire:NUMAVg 8

3. Never precede a star (*) command with a colon:

ACQuire:STATE 1;*OPC

Any commands that follow will be processed as if the star command was

not there so the commands,

ACQuire:MODe ENVel

ope;*OPC;NUMAVg 8

will set the acquisition mode to envelope and set the number of acquisitions

for averaging to 8.

4. When you concatenate queries, the responses to all the queries are

concatenated into a single response message. For example, if the display

graticule is set to Full and the display style is set to dotsonly, the concatenated

query

DISplay:GRAticule?;STYle:DOTsonly? will return the following.

If the header is on:

DISPLAY:GRATICULE FULL;:DISPLAY:STYLE:DOTSONLY 1

2-4 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual

Command Syntax

If the header is

off:

FULL;1

1. Set commands and queries may be concatenated in the same message. For

example,

ACQuire:MODe SAMple;NUM AVg?;STATE?

is a valid message that sets the acquisition mode to sample. The message then

queries the number of acquisitions for averaging and the acquisition state.

Concatenated commands and queries are executed in the order received.

Here are some invalid concatenations:

DISPlay:STYle:DOTsonly OFF;ACQuire:NUMAVg 8 (no colon before

ACQuire)

DISPlay:GRAticule FULL;:STYle:DOTSONLY OFF (extra colon before

STYle.

DISPlay:GRAticule FULL;:*TRG (colon before a star (*) command)

MATH:HORizontal:SCAle 1.0e-1;HORizontal:POSition 5.0el

(levels of the mnemonics are different; either remove the second use of

HORizontal: or place :MATH in front of HORizontal:POSition)

Terminating

This documentation uses <EOM> (End of Message) to represent a message

terminator.

Table 2-4: End of Message Terminator

Sym

bol

Mea

ning

OM>

Message terminator

The end-of-message terminator must be the END message (EOI asserted

concurrently with the last data byte). The last data byte may be an ASCII line

feed (LF) character.

This oscilloscope does not support ASCII LF only message termination. The

oscilloscope always terminates outgoing messages with LF and EOI.

Constructed Mnemonics

Some header mnemonics specify one of a range of mnemonics. For example, a

channel mnemonic can be CH1, CH2, CH3, or CH4. You use these mnemonics

in the command just as you do any other mnemonic. For example, there is a

CH1:POSition command, and there is also a CH2:POSi tion command. In the

command descriptions, this list of choices is abbreviated as CH<x>.

MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-5

Command Syntax

Cursor Position

Mnemonics

When cursors ar

e displayed, commands may specify which cursor of the pair to

use.

Table 2-5: Channel Mnemonics

Symbol Meaning

CH<x> A channel speciﬁer; <x> is 1 through 4.

Table 2-6: Cursor Mnemonics

Symbol Meaning

CURSOR<x>

A cursor selector; <x> is either 1 or 2.

POSITION<x>

A cursor selector; <x> is either 1 or 2.

HPOS<x>

A cursor selector; <x> is either 1 or 2.

Math Spe

ciﬁer Mnemonics

Commands can specify the mathematical waveform to use as a mnemonic in

the header.

Table 2-7: Math S peciﬁer Mnemonics

Symbol Meaning

Math<x>

A math waveform speciﬁer; <x> is 1.

Measurement Spec iﬁer

Mnemonics

Commands can specify which measurement to set or query as a mnemonic in the

header. Up to eight automated measurements may be displayed.

Table 2-8: Measurement Speciﬁer Mnemonics

Symbol Meaning

MEAS<x> A measurement speciﬁer; <x> is 1 through 8.

hannel Mnemonics

Commands specify the channel to use as a mnemonic in the header.

Reference Waveform

Mnemonics

Commands can specify the reference waveform to use as a mnemonic in the

header.

Table 2-9: Reference Waveform Mnemonics

Symbol Meaning

REF<x>

A reference waveform speciﬁer; <x> is 1, 2, 3, or 4 for 4-channel

oscilloscopes and 1 or 2 for 2-channel oscilloscopes.

2-6 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual