Keithley 2001 User Manual

IEEE-488 Reference
4-124
An alternate way to set the integration rate is by programming the aperture, which is seconds per
integration (see :APERture command). If the aperture is already known, the following equation
can be used to determine the number of power line cycles per integration (NPLC):
NPLC = Aperture × f
where; NPLC is the number of power line cycles per integration.
Aperture is the integration period in seconds per integration.
f is the power line frequency (Note: For 400Hz line power, use 50Hz to calculate ap-
erture).
Keep in mind that when the integration period is set using the :NPLCycles command, the time
value for the :APERture command will change accordingly to reflect the new integration rate.
Conversely, if the integration period is set using the :APERture command, the value for the
:NPLCycle command will change accordingly.
On power-up, the instrument will use the NPLC value to determine the integration period. Thus,
if using a different power line frequency, the NPLC value will remain the same, but the aperture
time value may change.
Note: If line synchronization is enabled (see:LSYNc command in SYSTem subsystem), the in-
tegration period will not start until the beginning of the next power line cycle. For example, if a
reading is triggered at the positive peak of a power line cycle, the integration period will not start
until that power line cycle is completed. The integration period starts when the positive-going
sine wave crosses zero volts. See paragraph 3.12 for more details.
Programming example 10 OUTPUT 716; “:curr:ac:nplc 2; nplc?”
20 ENTER 716; A$
30 PRINT A$
40 END
Line 10 Sets the integration rate for two cycles per measurement, and then queries the NPLC
value.
Line 20 Addresses the Model 2001 to talk.
Line 30 Displays the programmed NPLC value (2).
:AUTO <b>|ONCE
[:SENSe[1]]:CURRent:AC:NPLCycles:AUTO <b>|ONCE Control auto NPLC for ACI
[:SENSe[1]]:CURRent[:DC]:NPLCycles:AUTO <b>|ONCE Control auto NPLC for DCI
[:SENSe[1]]:VOLTage:AC:NPLCycles:AUTO <b>|ONCE Control auto NPLC for ACV
[:SENSe[1]]:VOLTage[:DC]:NPLCycles:AUTO <b>|ONCE Control auto NPLC for DCV
[:SENSe[1]]:RESistance:NPLCycles:AUTO <b>|ONCE Control auto NPLC for Ω2
[:SENSe[1]]:FRESistance:NPLCycles:AUTO <b>|ONCE Control auto NPLC for Ω4
[:SENSe[1]]:TEMPerature:NPLCycles:AUTO <b>|ONCE Control auto NPLC for TEMP
Parameters <b> = 1 or ON Enable auto NPLC
= 0 or OFF Disable auto NPLC
ONCE Enable and then disable auto NPLC

Keithley 2001 Specifications

General

Brand	Keithley
Model	2001
Category	Multimeter
Language	English