Ceyear 4051 Series, User Manual

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6 Remote control
6.1 Basis of Remote Control
621
7) Command line structure
One command line may include multiple SCPI commands. The following methods can be applied to end the
current command line:
 Enter;
 Enter key and EOI;
 EOI and the last byte.
Commands in the command line are separated by semicolons. Commands of different subsystems begin with
the colon. For example:
MMEM:COPY "Test1", "MeasurementXY";:HCOP:ITEM ALL
This command line includes two commands, the first of which is the MMEM subsystem command and the
second of which is the HCOP subsystem command. If adjacent commands belong to the same subsystem and
the command paths are subject to partial overlapping, the commands can be abbreviated. For example:
HCOP:ITEM ALL;:HCOP:IMM
This command line includes tow commands which belong to the same level of the HCOP subsystem. The
second command is started at the level lower than the HCOP command, and the colon at the beginning of the
command can be omitted. The command line can be abbreviated as follows:
HCOP:ITEM ALL;IMM
6.1.4 Command Sequence and Synchronization
IEEE488.2 defines the difference of the overlapping command and continuous command.
 The continuous command refers to the command sequence to be executed continuously. Generally, the
speed of command execution is high.
 The overlapping command refers the command which is not executed automatically before execution of
next command. The processing time of the overlapping command is generally long. The program is
allowed to process other events synchronously.
Even if one command line includes multiple setting commands, commands may not be executed according to
the reception sequence. In order to execute each command according to a certain sequence, all the commands
must be transmitted as a separate command line.
Example: command line including setting and query commands.
If one command line includes query commands, query results are unpredictable. The returned value will be
fixed if the following command is entered:
:FREQ:STAR 1GHZ;SPAN 100;:FREQ:STAR?
Returned value: 1000000000 (1GHz)
The returned value will not be fixed if the following command is entered:
:FREQ:STAR 1GHz;STAR?;SPAN 1000000
The returned result may be the current starting frequency of the instrument before command sending, as the
commands will be executed one by one by the host program after command messages are received. The
returned result may be 1GHz in the case of execution after the commands are received by the host program.
Prompt
Setting commands and query commands are sent separately.
General rules: setting commands and query commands should be sent in different program messages in order
to ensure that the returned results of query commands are correct.