Triggering Setup; Delay Time; Ac Bandwidth; Offset Compensation - Agilent Technologies 3458A User Manual

Triggering Setup

Delay Time

AC Bandwidth

Offset Compensation

High-Speed DCV
Example
10 OUTPUT 722;"PRESET FAST"
20 OUTPUT 722;"APER 1.4E-6"
25
30 OUTPUT 722;"MFORMAT SINT"
40 OUTPUT 722;"MEM FIFO"
50 OUTPUT 722;"NRDGS 10000,AUTO
60 OUTPUT 722;"TARM SGL"
70 END
High-Speed OHM (or
OHMF) Example
10 OUTPUT 722;"PRESET FAST"
20 OUTPUT 722;"APER 1.4E-6"
25
30 OUTPUT 722;"MFORMAT SINT"
40 OUTPUT 722;"MEM FIFO"
50 OUTPUT 722;"OHM 100E3"
60 OUTPUT 722;"NRDGS 10000,AUTO"
Frequency or period measurements: The integration time does not affect
frequency or period measurements. For these measurements, the specified
resolution (which also selects gate time) has a major effect on the reading
rate. The specifications in Appendix A show reading rates for frequency and
period measurements based on the specified resolution.
To ensure the fastest triggering configuration, set the trigger arm, trigger,
and sample events to AUTO, You can also use the TIMER sample event (or
the SWEEP command). Assuming you do not generate the TRIGGER TOO
FAST error, the reading rate is the reciprocal of the TIMER or SWEEP
interval.
Under normal operation, the multimeter automatically determines a delay
time (default delay) based on the present measurement function, range,
resolution, and for AC measurements, the AC bandwidth setting. This delay
time is actually the settling time inserted before the first reading, which
ensures accurate readings. The default delay has a large affect on the reading
rate for analog AC measurements and a minimal affect on the reading rate
for sampled AC voltage or DC measurements. For analog AC measurements,
you can achieve a faster reading rate by specifying a shorter delay than the
default value. However, the resulting settling time may not produce accurate
measurements.
For the fastest AC measurements, specify the AC bandwidth (ACBAND
command) to match the frequency content of the input signal. The
specifications in Appendix A show the reading rates for AC measurements
based on the frequency components of the input signal.
For 2- and 4-wire ohms measurements with offset compensation enabled, an
offset voltage measurement is made before each resistance reading. This
requires more time than with offset compensation disabled (OCOMP OFF).
The following program measures DC voltage at the fastest. possible rate (>
100k readings per second). The readings are stored in reading memory.
!DCV, 10V RANGE, TARM SYN, TRIG AUTO
!LONGEST INTEGRATION TIME POSSIBLE FOR
!>100K READINGS PER SECOND
!SINT MEMORY FORMAT
!ENABLE READING MEMORY
!10000 READINGS/TRIGGER, AUTO SAMPLE EVENT
!TRIGGER READINGS
The following program measures 2-wire ohms at the fastest possible rate (>
100k readings per second). This program can be adapted to 4-wire ohms by
using the OHMF command instead of the OHM command in line 50.
!DCV 10V RANGE, TARM SYN, TRIG AUTO
!LONGEST INTEGRATION TIME POSSIBLE FOR
!>1OOK READINGS PER SECOND
!SINT MEMORY FORMAT
!ENABLE READING MEMORY
!2-WIRE OHMS, 100K(W) RANGE
!10000 READINGS/TRIGGER, AUTO SAMPLE EVENT
Chapter 4 Making Measurements 105