Technical data

Instrument Model
SCPI guidelines require that the Serial BERT is compatible with an instrument
model. This ensures that when using SCPI, functional compatibility is achieved
between instruments that perform the same tasks. For example, if two different
instruments have a programmable clock frequency setting, then both instruments
would use the same SCPI commands to set their frequency. The instrument model
is made up of a number of subsystems.
The sub-system defines a group of functions within a module and has a unique
identifier under SCPI, which is called the Root Keyword.
For more details on the instrument model, see “Serial BERT Register Model” on
page 27.
Command Syntax
Commands may be up to twelve characters long. A short-form version is also
available which has a preferred length of four characters or less. In this document
the long-form and short-form versions are shown as a single word with the short-
form being shown in upper-case letters.
For example, the long-form node command SOURce has the short-form SOUR.
Using the short form saves time when entering a program, however, using the long
form makes a program more descriptive and easier to understand.
SCPI commands may be commands only, commands and queries, or queries only.
A question mark at the end of a command indicates that it is a query. If the question
mark appears in brackets ([?]), the command has a command and query form.
Note that some queries can be combined with an additional keyword that impacts
the response.
For example:
SOURce9:SSCLocking:FREQuency?
returns the present value.
SOURce9:SSCLocking:FREQuency? MIN
returns the minimum acceptable value.
SOURce9:SSCLocking:FREQuency? MAX
returns the maximum acceptable value.
In this manual, the syntax
SOURce9:SIN:FREQ? MIN | MAX
is used for this type of queries.
SCPI Command Language 4
Agilent J-BERT N4903B High-Performance Serial BERT 83