Chapter 4 Remote Interface Reference

An Introduction to the SCPI Language

Querying Parameter Settings

You can query the value of most parameters by adding a question mark (?) to the command. For example, the following command sets the output current to 5 amps:

‘‘CURR 5’’

You can query the value by executing:

 

‘‘CURR?’’

 

You can also query the minimum or maximum value allowed with the present

 

function as follows:

 

‘‘CURR? MAX’’

 

‘‘CURR? MIN’’

 

 

C a u t i o n

If you send two query commands without reading the response from the first,

 

and then attempt to read the second response, you may receive some data

 

from the first response followed by the complete second response. To avoid

 

this, do not send a query command without reading the response. When you

 

cannot avoid this situation, send a device clear before sending the second

 

query command.

 

 

SCPI Command Terminators

A command string sent to the power supply must terminate with a <new line> character. The IEEE-488 EOI (end-or-identify) message is interpreted as a <new line> character and can be used to terminate a command string in place of a <new line> character. A <carriage return> followed by a <new line> is also accepted. Command string termination will always reset the current SCPI command path to the root level. The <new line> character has the ASCII decimal code of 10.

IEEE-488.2 Common Commands

The IEEE-488.2 standard defines a set of common commands that perform functions like reset, self-test, and status operations. Common commands always begin with an asterisk ( * ), are four to five characters in length, and may include one or more parameters. The command keyword is separated from the first parameter by a blank space. Use a semicolon ( ; ) to separate multiple commands as shown below:

‘‘*RST; *CLS; *ESE 32; *OPC?

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Agilent Technologies E3632A manual Querying Parameter Settings, Scpi Command Terminators, IEEE-488.2 Common Commands