Rohde & Schwarz SML01, Руководство по эксплуатации

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R&S®SML / R&S®SMV03 Instrument Model and Command Processing
1090.3123.12 E-6 5.13
Instrument Model and Command Processing
The instrument model shown in Fig. 5-2 was created with a view to the processing of IEC/IEEE-bus
commands. The individual components work independently of each other and simultaneously. They
communicate with each other by means of messages.
IEC/IEEE
bus
Input unit
with
input buffer
Command
recognition
Data set
Instrument
hardware
IEC/IEEE
bus
Status reporting
system
Output unit
with
output buffer
Fig. 5-2 Device model for remote control via the IEC/IEEE bus
Input Unit
The input unit receives commands character by character from the IEC/IEEE bus and stores them in the
input buffer. The input buffer has a size of 256 characters. The input unit sends a message to the
command recognition when the input buffer is full or when it receives a terminator, <PROGRAM
MESSAGE TERMINATOR>, as defined in IEEE 488.2, or the interface message DCL.
If the input buffer is full, the IEC/IEEE-bus traffic is stopped and the data received up to then are
processed. After this, the IEC/IEEE-bus traffic is continued. If, on receipt of a terminator, the input buffer
is not full, the input unit can receive the next command during command recognition and execution.
Receipt of a DCL command clears the input buffer and immediately initiates a message to the
command recognition.