Model 6487 Reference Manual
Buffer and Sweeps
6-5
klqb
The Model 6487 uses IEEE-754 floating point format for statistics calculations.
When programming the buffer via remote, the trigger count set with the
TRIG:COUN command should normally equal the number of buffer readings to
store set with TRAC:POIN. See
for details on triggering.
If the voltage source was in compliance when the reading was acquired, the
recalled front panel SRC: display will show the voltage value dimmed. Over the
GPIB, a value of -999 returned for the voltage source element indicates that the
source was in compliance.
For any ohms measurements, the ohms reading is invalid and unknown if the
voltage source is in compliance. Therefore, a value of -9.9e+36 will be returned
over the GPIB and the message I-LIMIT will be displayed on the front panel for
both normal readings and buffer recall readings for any ohms readings where
the voltage source went into compliance.
Table 6-1
SCPI commands — buffer
Commands
Description
Default
Ref
:TRACe
:CLEar
:FREE?
:POINts <n>
:ACTual?
:FEED <name>
:CONTrol <name>
:TSTamp
:FORMat <name>
:DATA?
:MODE?
TRACe Subsystem:
Clear readings from buffer.
Query bytes available and bytes in use.
Specify number of readings to store: 1 to 3000.
Returns number of readings actually stored in buffer.
Select source of readings: SENSe[1], CALCulate[1], or
CALCulate2.
Select buffer control mode: NEVer or NEXT.
Timestamp:
Select timestamp format: ABSolute or DELTa.
Read all readings in buffer.
Query the type of data (DC or AVOL) stored in the
buffer.
See Note
100
SENS1
NEV
ABS
A
B
C
D
E
:FORMat
:ELEMents <list>
FORMat Subsystem:
Specify data elements for :TRACe:DATA? response
message: READing, UNITs, VSOurce, TIME,
STATus, ALL, or DEFault (all elements except
VSOurce).
All
except
VSO
F
:CALCulate3
:FORMat <name>
:DATA?
CALCulate3 Subsystem:
Select buffer statistic: MINimum, MAXimum, MEAN,
SDEViation, or PKPK.
Read the selected buffer statistic.
MEAN
G
H
Note: SYSTem:PRESet and *RST have no effect on :TRACe commands. The listed defaults are power-on defaults.
