Agilent Technologies Agilent 86120C manual READ command, FETCh command

Programming

Making Measurements

A common programming error is to send the :MEASure command when the instrument is in the continuous measurement acquisition mode. Because :MEASure contains an :INIT:IMM command, which expects the single measurement acquisition mode, an error is gener- ated, and the INIT command is ignored.

:READ command

The READ command works like the MEASure command except that it does not configure the instrument’s settings. You can use the CONFig- ure command to configure the instrument for a particular measure- ment without returning any data.

The MEASure and READ commands are identical to combining the fol- lowing commands:

Command Equivalent Commands

:MEASure :ABORt;:CONFigure;:READ

:READ:ABORt;:INITiate:IMMediate;:FETCh

A common programming error is to send the :READ command when the instrument is in the continuous measurement acquisition mode. Because :READ contains an :INIT:IMM command, which expects the single measurement acquisition mode, an error is generated, and the INIT command is ignored.

:FETCh command

The FETCh command returns data from previously performed mea- surements; it does not initiate the collection of new data. Because FETCh does not configure the instrument or acquire new input data, you can use FETCh repeatedly on the same set of acquired data. For example, use two FETCh commands to return wavelength and then power values for the same measurement. This is shown in the follow- ing program fragment:

OUTPUT 720;”:INIT:CONT OFF;”

OUTPUT 720;”:CONF:ARR:POW MAX”

OUTPUT 720;”:INIT:IMM”

OUTPUT 720;”:FETC:ARR:POW?”

ENTER 720:powers$

OUTPUT 720;”:FETC:ARR:POW:WAV?”

ENTER 720:wavelengths$

In the example above, the data in the power and wavelength arrays are returned in the same order so that powers can be matched to wave- lengths.

3-10