FORMat

The FORMat command subsystem is used to specify the output format of the readings from the HP E1429 Digitizer.

Subsystem FORMat

Syntax [:DATA] <type>[,<length>]

[:DATA]

FORMat[:DATA] <type>[,<length>] specifies the output format for measurement data.

Parameters

Parameter

Parameter

Range of

Default

Name

Type

Values

Units

 

 

 

 

type

discrete

ASCiiPACKed REAL

none

 

 

 

 

length

numeric

9 (ASCii)16 (PACKed)

none

 

 

64 (REAL)

 

 

 

 

 

Comments PACKed format is signed 16 bits, however, the original 12-bit reading is shifted left 4 bits and the lower most 4 bits are 0 filled. Thus, to get the actual value of the reading, the packed value should be divided by 16. Packed readings always represent a value between -1.023 and +1.0235 (i.e. there is no correction done internally for the range setting), and further post-processing by the user is necessary to get the actual reading value if the SENSe<chan >:VOLTage:RANGe setting is not 1V.

REAL,64 format sends data back as IEEE-754 64-bit real numbers. The data is converted internally to reflect the SENSe<chan >:VOLTage:RANGe setting, and no further conversion is needed by the user.

Both PACKed,16 and REAL,64 formats return data preceded by the IEEE-488.2 definite length arbitrary block header. The header is as follows:

#<num_digits > <num_bytes >

#signifies a block transfer

<num_digits > is a single digit (1 through 9) which specifies how many digits (ASCII characters) are in the <num_bytes > descriptor which follows <num_bytes > is the number of data bytes which immediately follow the <num_bytes > field

228 Command Reference

FORMat Subsystem

Page 228
Image 228
HP E1429A manual Subsystem FORMat