Keithley 2001 User Manual

IEEE-488 Reference
4-51
4.11
Signal oriented measurement commands
The signal oriented command group is used to acquire readings using a set of high-level instruc-
tions to control the measurement process. These commands are summarized in Table 4-5.
:FETCh?
Format
:fetc?
Description
This query command is used to request a post-processed reading. After sending this command
and addressing the Model 2001 to talk, a reading will be sent to the computer. This command
does not affect the instrument setup.
The type of reading (latest or fresh) that is requested depends on which fetch format is selected;
SCPI or FRESh.
With the SCPI fetch format selected, :FETCh? simply requests the last available reading. Note
that this command can repeatedly return the same reading. In the absence of a new reading,
:FETCh? will simply return the old reading.
With the FRESh fetch format selected, :FETCh? is used to return a new (fresh) reading. In this
format, you cannot use :FETCh? to return the same reading more than once. If :FETCh? is sent
again, it will wait until a new reading is triggered and available. In this format, :FETCh? operates
the same as the [:SENSe[1]]:DATA:FRESh? command.
At power-on, the fetch format is set to FRESh. The fetch format can be changed using the :SYS-
Tem:FETch:FORMat command. Note that the fetch format is not affected by *RST or :SYS-
Tem:PRESet.
Programming example
10 OUTPUT 716; “:syst:pres”
20 OUTPUT 716; “:fetch?”
30 ENTER 716; A$
40 PRINT A$
50 END
Line 10 Selects the :SYSTem:PRESet default conditions.
Line 20 Reads the latest measurement.
Line 30 Addresses the Model 2001 to talk.
Line 40 Displays the reading on the computer CRT.
Table 4-5
Signal oriented measurement command summary
Command Description
:FETCh? Requests the latest reading (SCPI) or a fresh reading (FRESh).
:CONFigure:<function> Places the 2001 in a “one-shot” measurement mode for the specified function.
:READ? Performs an :ABORt, :INITiate, and a :FETCh?.
:MEASure[:<function>]? Performs an :ABORt, :CONFigure:<function>, and a :READ?.

Keithley 2001 Specifications

General

Model	2001
Category	Multimeter
Manufacturer	Keithley
Type	Digital Multimeter
Digits of Resolution	7.5
DC Voltage Range	100 mV to 1000 V
AC Voltage Range	100 mV to 750 V
Frequency Range	3 Hz to 500 kHz
Connectivity	GPIB, RS-232
Display	VFD
Resistance Accuracy	0.008% + 2.0 mΩ
Frequency Accuracy	±0.01%
DC Current Range	10 μA to 3 A
AC Current Range	10 μA to 3 A
Power Supply	100 V to 240 V AC, 45 Hz to 66 Hz