Remote Control Basics
R&S
®
SMB100A
237
Operating Manual 1407.0806.32 ─ 21
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Instrument messages
Instrument messages are employed in the same way for all interfaces, if not indica-
ted otherwise in the description. Structure and syntax of the instrument messages
are described in
Chapter 6.3, "SCPI Command Structure"
description of all messages available for the instrument is provided in the chapter
"Remote Control Commands".
There are different types of instrument messages, depending on the direction they
are sent:
–
Commands
–
Instrument responses
Commands
Commands (program messages) are messages the controller sends to the instrument.
They operate the instrument functions and request information. The commands are
subdivided according to two criteria:
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According to the effect they have on the instrument:
–
Setting commands
cause instrument settings such as a reset of the instru-
ment or setting the frequency.
–
Queries
cause data to be provided for remote control, e.g. for identification of
the instrument or polling a parameter value. Queries are formed by directly
appending a question mark to the command header.
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According to their definition in standards:
–
Common commands
: their function and syntax are precisely defined in stan-
dard IEEE 488.2. They are employed identically on all instruments (if imple-
mented). They refer to functions such as management of the standardized sta-
tus 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 confirmed" 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.
6.1.3 LAN Interface
To be integrated in a LAN, the instrument is equipped with a LAN interface, consisting
of a connector, a network interface card and protocols. For remote control via a net-
work, the PC and the instrument must be connected via the LAN interface to a com-
mon network with TCP/IP network protocol. They are connected using a commercial
RJ45 cable. The TCP/IP network protocol and the associated network services are
Remote Control Interfaces and Protocols
