Keithley 2790, Reference Manual

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14-6 Model 2790 SourceMeter
®
Switch System Reference Manual
FORMat:ELEMents <item list>
Parameters
READing = DMM reading*
UNITs = Units*
TSTamp = Timestamp*
RNUMber = Reading number
CHANnel = Channel number*
LIMits = Limits reading
*Included as factory default selections.
The specified elements are included in the data string in response to FETCh?, READ?,
MEASure?, and TRACe:DATA?. Note that each element in the item list must be separated
by a comma (i.e. send “FORMat:ELEMents READing, UNITs, TSTamp, RNUMber,
CHANnel, LIMits” to include all elements in the data string). The elements for the ASCii
format are shown in
Figure 14-1 .
An overflow reading is returned as +9.9E37. When a specified data element has invalid
data associated with it, NAN (Not A Number) will be the response. NAN is returned as
+9.9E37.
Timestamp — Timestamp references the returned data string to a point in time. There are
two timestamps: relative and real-time clock. The following command selects the
timestamp:
SYSTem:TSTamp:TYPE <name> ' Select timestamp type; RELative or RTCL.
klqb
The real-time clock timestamp can only be returned for the ASCII data format.
For the binary formats, timestamp will not be sent with the real-time clock
selected.
The relative timestamp operates as a timer that starts at zero seconds when the instrument
is turned on, or when the relative timestamp is reset (SYSTem:TSTamp:RELative:RESet).
After 99,999.99 seconds, the timer resets back to zero and starts over.
For buffer readings recalled from the front panel, the relative timestamp is referenced to
the first reading stored in the buffer (absolute format) which is timestamped at 0 seconds
and to the time between each stored reading (delta format). For remote programming, you
can only return the absolute or delta timestamp. The following command is used to select
relative timestamp format for the buffer:
TRACe:TSTamp:FORMat ' Select timestamp format; ABSolute or DELTa.
Reading number — The reading counter starts at zero when the Model 2790 is turned on.
When returning buffer readings using TRACe:DATA?, each reading will be referenced to
the first reading, which is #0. The following command will reset the counter:
SYSTem:RNUMber:RESet.