Keithley 2750 User Manual

Model 2750 Multimeter/Switch System User’s Manual FORMat and Misc SYSTem Commands 14-3
ASCII data format
The ASCII data format is in a direct readable form for the operator. Most programming
languages easily convert ASCII mantissa and exponent to other formats. However, some
speed is compromised to accommodate the conversion. Figure 14-1 shows an example
ASCII string that includes all the data elements. See “FORMat:ELEMents <item list>,”
page 14-5, for information on the data elements.
Figure 14-1 also shows the byte order of the data string. Data elements not specified by the
:ELEMents command are simply not included in the string.
Figure 14-1
ASCII data format
IEEE-754 single precision format
REAL, 32, or SREal will select the binary IEEE-754 single precision data format.
Figure 14-2A shows the normal byte order format for each data element. For example, if
three data elements are selected, the data string for each reading conversion is made up of
three 4-byte data blocks. Note that the data string for each reading conversion is preceded
by a 2-byte header that is the binary equivalent of an ASCII # sign and 0. Figure 14-2 does
not show the byte for the terminator that is attached to the end of each data string. Note
that the byte order of the data string can be sent in reverse order (see “FORMat:BORDer
<name>,” page 14-6).
REAL, 64, or DREal selects the binary IEEE754 double precision data format and is
shown in Figure 14-2B (normal byte order shown). This format is similar to the single pre-
cision format except that it is 64 bits long.
+1.23456789E-03VDC, +11.664SECS, +236RDNG, 000, 0000LIMITS
Reading* Timestamp
Units
Channel
Number
Limits
Code
Reading
Number
Units:
VDC = DC Volts
VAC = AC Volts
ADC = DC Current
AAC = AC Current
OHM = 2-Wire Resistance or Continuity
OHM4W = 4-Wire Resistance
*An overflow reading is displayed as +9.9E37 with no limits.
Units:
HZ = Frequency
SECS = Period
C = Temperature in ˚C
F = Temperature in ˚F
K = Temperature in ˚K
2750-900-01.book Page 3 Wednesday, August 3, 2011 7:56 AM

Keithley 2750 Specifications

General

Brand	Keithley
Model	2750
Category	Switch
Language	English