User manual

Remote Control
R&S
®
RTO
393User Manual 1316.0827.02 ─ 06
– Common commands: their function and syntax are precisely defined in standard
IEEE 488.2. They are employed identically on all instruments (if implemented).
They refer to functions such as management of the standardized status registers,
reset and self test.
– Instrument control commands refer to functions depending on the features of
the instrument such as frequency settings. Many of these commands have also
been standardized by the SCPI committee. These commands are marked as
"SCPI compliant" in the command reference chapters. Commands without this
SCPI label are device-specific, however, their syntax follows SCPI rules as per-
mitted by the standard.
Instrument responses
Instrument responses (response messages and service requests) are messages the
instrument sends to the controller after a query. They can contain measurement results,
instrument settings and information on the instrument status.
See also:
● Structure and syntax of the instrument messages are described in chapter 16.1.4,
"SCPI Command Structure", on page 395.
● Detailed description of all messages: chapter 16.2, "Command Refer-
ence", on page 418
16.1.3.2 Interface Massages
Interface messages are transmitted to the instrument on the data lines. They are used to
communicate between the controller and the instrument. Interface messages can only
be sent by instruments that have GPIB bus functionality.
GPIB Interface Messages
Interface messages are transmitted to the instrument on the data lines, with the attention
line (ATN) being active (LOW). They are used for communication between the controller
and the instrument and can only be sent by a computer which has the function of a GPIB
bus controller. GPIB interface messages can be further subdivided into:
●
Universal commands: act on all instruments connected to the GPIB bus without
previous addressing
●
Addressed commands: only act on instruments previously addressed as listeners
Universal Commands
Universal commands are encoded in the range 10 through 1F hex. They affect all instru-
ments connected to the bus and do not require addressing.
Command Effect on the instrument
DCL (Device Clear) Aborts the processing of the commands just received and sets the command
processing software to a defined initial state. Does not change the instrument
settings.
IFC (Interface Clear) *) Resets the interfaces to the default setting.
Basics