FORMat[:DATA]

ASCii,9 format sends data back as comma separated ASCII numbers. The data is converted internally to reflect the SENSe<chan >:VOLTage:RANGe setting, and no further conversion is needed by the user. The optional parameter 9 is the number of significant digits in the data. This parameter is always 9 and may not be changed. To read this data into an array, it is first necessary to determine how many readings are coming back from the FETCh? or READ? . If using FETCh?, then the FETCh:COUNt? command will specify how many readings will be returned. READ? requires the user to calculate in advance how many readings to expect. See the next comment below for details on how to calculate number of readings.

The number of readings that FETCh? or READ? will return for each channel can be calculated as:

(number of start triggers) * (pre-arm readings + post-arm readings)

The above equation may be built from the following queries:

(ARM:COUNt?) * (TRIGger:COUNt?)

To determine how many readings are pre-arm, take the absolute value of the number returned by the SENSe:SWEep:OFFSet:POINts? query.

Related Commands: READ?, FETCh?

*RST Condition: FORMat:DATA ASCii,9

Example 1 Setting the data format to 64 bit reals

FORM REAL

Output data in 64 bit real format, the ",64"

 

is defaulted

Example 2 Reading back PACKed data (HP BASIC program)

DIM Ndig$[1],Count$[9]

Dimension parameters for header

ASSIGN @X TO 70905;FORMAT OFF

Turn format off for array data

 

OUTPUT 70905;"FETC1?"

Query for channel 1 measurement data

ENTER @X USING "#,X,K,K";Ndig$;Count$[1;VAL(Ndig$)]

 

Strip the header preceeding the data

ALLOCATE INTEGER Meas_data(1:VAL(Count$)/2)

 

Allocate an array to hold the data

ENTER @X;Meas_data(*)

Read in the measurement data

ENTER 70905 USING "B";Junk

Need to strip off left over line feed

FORMat Subsystem

Command Reference 229

Page 229
Image 229
HP E1429A manual FORMatDATA, ∙ Related Commands READ?, FETCh?, Example 1 Setting the data format to 64 bit reals