Specifications

FORMat
The FORMat subsystem provides commands to set and query the response data
format of readings returned using the [SENSe:]DATA:FIFO:¼? commands.
Subsystem Syntax FORMat
[:DATA] <format>[,<size>]
[:DATA]?
FORMat[:DATA]
FORMat[:DATA] <format>[,<size>] sets the format for data returned using the
[SENSe:]DATA:FIFO:¼?, [SENSe:]DATA:CVTable and FETCh? commands.
Parameters
Parameter
Name
Parameter
Type
Range of
Values
Default
Units
format discrete (string) REAL | ASCii | PACKed none
size numeric for ASCii, 7
for REAL, 32 | 64
for PACKed, 64
none
Comments
·
The REAL format is IEEE-754 Floating Point representation.
·
REAL, 32 provides the highest data transfer performance since no format
conversion step is placed between reading and returning the data. The default size
for the REAL format is 32 bits. Also see DIAG:IEEE command.
·
PACKed, 64 returns the same values as REAL, 64 except for Not-a-Number
(NaN), IEEE +INF, and IEEE -INF. The NaN, IEEE +INF, and IEEE -INF values
returned by PACKed,64 are in a form compatible with HP Workstation BASIC
and HP BASIC/UX (see table on following page).
·
REAL 32, REAL 64, and PACK 64, readings are returned in the
IEEE-488.2-1987 Arbitrary Block Data format. The Block Data may be either
Definite Length or Indefinite Length depending on the data query command
executed. These data return formats are explained in “Arbitrary Block Program
Data” on page 180 of this chapter. For REAL 32, readings are 4 bytes in length
(C-SCPI type is float32 array). For REAL 64 and PACK, 64, readings are
8 bytes in length (C-SCPI type is float64 array).
·
ASCii is the default format. ASCII readings are returned in the form
±1.234567E±123. For example 13.325 volts would be +1.3325000E+001. Each
reading is followed by a comma (,). A line feed (LF) and End-Or-Identify (EOI)
follow the last reading (C-SCPI type is string array).
Chapter 6 229
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