Agilent Technologies E1326B User Manual page 269

Avoid Function
Changes
Avoid Aperture
Changes
Minimize the Number
of Command/
Response Sessions
270 Measurement Speed and Accuracy Tradeoffs
The E1326B multimeter (DMM) takes time to switch between its various
functions because the hardware is reconfigured and calibration constants for
the new function are retrieved. Organize your program so all measurements
on a function are done at the same time. This is best accomplished with a
scan list. For example:
10 OUTPUT @Dmm;"MEAS:VOLT:DC? (@100:103)"
20 ENTER @Dmm;Dc_readings(*)
30 OUTPUT @Dmm;"MEAS:RES? (@105,107)"
40 ENTER @Dmm;Res_readings(*)
Changing apertures takes a significant amount of time because the
multimeter retrieves new calibration constants from its calibration memory
and prepares to use them. The easiest way to avoid aperture changes is to
directly specify the aperture time. This requires that you not use the
command and that you not specify the optional
MEASure
parameter in a CONFigure
10 OUTPUT @Dmm;"CONF:VOLT:DC (@100:103);:VOLT:APER 100e-6;:READ?"
20 ENTER @Dmm;Dc_readings(*)
Minimizing the number of command/response sessions involves
programming the multimeter to pace itself, rather than the computer pacing
the multimeter. The SAMPle TIMer
or for multiple channel scanning with the FET multiplexers (see page 58).
The will generate an error message if the multimeter cannot
SAMPle TIMer
keep up. For example:
10 OUTPUT @Dmm;"CONF:VOLT:DC;:VOLT:APER 100e-6;"
20 OUTPUT @Dmm;"SAMP:SOUR TIM;SAMP:TIM .02;SAMP:COUNT 200;:READ?"
30 DIM Reading(1:200)
40 ENTER @Dmm;Reading(*)
The
EXTernal TRIGger
external signal. In the HP E1300/E1301 mainframe the built-in pacer is a
convenient source for an external signal. A potential problem is that if an
external trigger arrives before the multimeter is ready to start a new scan,
the trigger will be missed and no error message is generated. For example:
10 OUTPUT @Dmm;"CONF:VOLT:DC (@100:109);:VOLT:APER 100e-6;"
20 OUTPUT @Dmm;"TRIG:SOUR EXT;TRIG:COUNT 200;:READ?"
30 OUTPUT @Sys;"PULSE:PER .02;PULSE:COUN 200;:INIT"
40 DIM Reading(1:200)
50 ENTER @Dmm;Reading(*)
command. For example:
should be used for single channel pacing
input can be used to start a scan based on an
resolution
< >
Appendix D