Scpi Command Structure - R&S NGL200 Series User Manual

®
R&S NGL200/NGM200
are device-specific, however, their syntax follows SCPI rules as permitted by the
standard.
Instrument responses
Instrument responses (response messages and service requests) are messages which
the instrument sends to the controller after a query. They can contain measurement
results, instrument settings and information on the instrument status.
GPIB Interface Messages
Interface messages are transmitted to the instrument on the data lines with the atten-
tion line (ATN) being active (LOW). They are used for communication between the con-
troller and the instrument and can only be sent by a PC 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; universal commands are encoded in the range 10 through 1F
hex. They affect all instruments connected to the bus and do not require address-
ing.
●
Addressed commands only act on instruments previously addressed as listeners;
addressed commands are encoded in the range 00 through 0F hex. They only
affect instruments addressed as listeners.
A.1.2 SCPI Command Structure
SCPI commands consist of a so-called header and, usually, one or more parameters.
The header and the parameters are separated by a whitespace. The headers can con-
sist of several mnemonics (keywords). Queries are formed by appending a question
mark directly to the header. The commands can be either device-specific or device-
independent (common commands). Common and device-specific commands differ in
their syntax.
Syntax for Common Commands
Common (= device-independent) commands consist of a header preceded by an aster-
isk (*) and possibly one or more parameters.
Table A-1: Examples of Common Commands
User Manual 1178.8736.02 ─ 05
Command
*RST
*ESE
*ESR?
*IDN?
Additional Basics on Remote Control
Messages and Command Structure
Command Name
Reset
Event Status Enable
Event Status Query
Identification Query
Description
Resets the instrument.
Sets the bits of the event status
enable registers.
Queries the content of the event
status register.
Queries the instrument identifica-
tion string.
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