Rohde & Schwarz R&S UPP, User Manual

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Remote Control - Fundamentals
R&S
®
UPP
650 User Manual 1411.1055.32 ─ 10
Common Commands are precisely defined by the IEEE 488.2 standard
in function and notation. They relate to functions
such as the management of standard status reg-
isters, reset and self-test.
Device-specific commands relate to functions that depend on device charac-
teristics such as the frequency setting. A large
number of these commands are also standar-
dized by the SCPI consortium. Device-specific
extensions following SCPI rules are permitted by
the standard.
Device responses (response messages and service request)
are messages sent by a device to the controller after a query. They can include mea-
surement results, device settings or information about device status (see
Chap-
ter 6.5.2, "Responses to Queries" , on page 653).
The structure and syntax of device-dependent messages are explained in the following
section.
6.5 SCPI Command Structure and Syntax
Commands consist of a header and usually one or more parameters. The header and
parameters are separated by a "white space" (ASCII code 0 to 9, 11 to 32 decimal, e.g.
space). Headers may be composed of several keywords. Queries are formed by add-
ing a question mark direct to the header.
The commands used in the following examples are not implemented in the instrument
in every case.
Common Commands
Non-device-specific commands consist of a header preceded by an asterisk "*" and
possibly one or more parameters.
Examples:
*RST
RESET
, resets the instrument
*ESE 253
EVENT STATUS ENABLE
, sets bits of the Event Status Enable Register
*ESR?
EVENT STATUS QUERY
, queries of the content of the Event Status register.
Device-specific commands
Hierarchy:
Device-specific commands have a hierarchic structure (see figure below). The different
levels are represented by compound headers. Headers at the highest level (root level)
have one keyword only. This keyword identifies a whole command system.
SCPI Command Structure and Syntax