beautypg.com

Tektronix AFG3000 User Manual

Page 79

background image

Syntax and Commands

AFG3000 Series Arbitrary/Function Generators Reference Manual

3-5

Creating Commands

SCPI commands are created by stringing together the nodes of a subsystem hier-
archy and separating each node by a colon.

In Figure 3-2, TRIGger is the root node and SEQuence, SLOPe, SOURce, and TIMer
are lower level nodes. To create an SCPI command, start with the root node
TRIGger and move down the tree structure adding nodes until you reach the end of
a branch. Most commands and some queries have parameters; you must include a
value for these parameters. The command descriptions, which begin on page 3-15,
list the valid values for all parameters.

For example, TRIGger:SEQuence:SOURce EXTernal is a valid SCPI command
created from the hierarchy tree in Figure 3-2.

Parameter Types

Parameters are indicated by angle brackets, such as . There are several
different types of parameters, as listed in Table 3-4. The parameter type is listed
after the parameter. Some parameter types are defined specifically for

the

arbi-

trary/function generator

command set and some are defined by SCPI.

Table 3-4: Parameter types used in syntax descriptions

Parameter type

Description

Example

arbitrary block

A block of data bytes

#512234xxxxx...
where 5 indicates that the follow-
ing 5 digits (12234) specify the
length of the data in bytes;
xxxxx... indicates the data

or

#0xxxxx...<&EOI>

boolean

Boolean numbers or values

ON or

≠ 0

OFF or 0

discrete

A list of specific values

MIN, MAX

binary

Binary numbers

#B0110

octal

Octal numbers

#Q75, #Q3

hexadecimal

Hexadecimal numbers (0-9, A-F) #HAA, #H1

NR1 numeric

Integers

0, 1, 15, -1

NR2 numeric

Decimal numbers

1.2, 3.141516, -6.5

NR3 numeric

Floating point numbers

3.1415E-9, -16.1E5

NRf numeric

Flexible decimal number that
may be type NR1, NR2, or NR3

See NR1, NR2, NR3 examples
in this table

string

Alphanumeric characters (must
be within quotation marks)

“Testing 1, 2, 3”