FETCh?
Syntax
FETCh?
Description
This command transfers readings from volatile memory to the instrument's output buffer where you can read them into your computer. The readings are not erased from memory when you read them. You can send the command multiple times to retrieve the same data in reading memory.
Remarks
The FETCh? command will wait until the measurement is complete to terminate.
Readings can be acquired during a scan using the multiplexer and digital modules or by the internal DMM independently (when a channel list is not specified).
You can store at least 500,000 readings in memory and all readings are automatically time stamped. If memory overflows, a status register bit is set and new readings will overwrite the first (oldest) readings stored. The most recent readings are always preserved.
Each time you start a new scan, the instrument clears all readings (including alarm data) stored in reading memory from the previous measurement. Therefore, the contents of memory are always from the most recent measurement.
When you abort a measurement (see ABORt command), the instrument will terminate any reading in progress (readings are not cleared from memory). The readings remain in memory and can be read until you clear them or initiate a new scan.
The output from this command is affected by the settings of the FORMat:READing commands. Depending on the formats selected, each reading may or may not be stored with measurement units, time stamp, channel number, and alarm status information. If readings are acquired using the internal DMM independently (without a multiplexer scan), the channel number will be logged as channel "0".
The *RST command will clear the scan list and set all measurement parameters to their factory settings. The Instrument Preset (SYSTem:PRESet command) will not clear the scan list; however, this command will clear reading memory and all stored statistical data.
The instrument clears all readings from memory when a new scan is initiated, when any measurement parameters are changed (CONFigure and SENSe commands), and when the triggering configuration is changed (TRIGger commands).
The instrument clears all readings from memory after a Factory Reset (*RST command), after an Instrument Preset (SYSTem:PRESet command), or when mainframe power is cycled.
Return Format
The command transfers all readings from memory (with formatting as set by the FORMat:READing commands) but does not erase them. Multiple responses are separated by commas.
Example
The following program segment shows how to use the FETCh? command with the CONFigure and INITiate commands. The ROUTe:SCAN command puts the two channels into the scan list (and redefines the scan list). The INITiate command places the instrument in the "wait-for-trigger" state, scans the specified channels when the rear-panel Ext Trig Input line is pulsed low, and then sends the readings to memory. The FETCh? command transfers the readings from memory to the instrument's output buffer.
CONF:VOLT:DC 10,0.003,(@1003,1008)
ROUT:SCAN (@1003,1008)
TRIG:SOUR EXT
INIT
FETC?
Typical Response: +4.27150000E-03,+1.32130000E-03