[SENSe:]CURRent:DC:NPLC
[SENSe:]CURRent:DC:NPLC
Syntax
[SENSe:]CURRent:DC:NPLC {<PLCs>|MIN|MAX}[,(@<ch_list>)]
[SENSe:]CURRent:DC:NPLC? [{(@<ch_list>)|MIN|MAX}]
Description
This command sets the integration time in number of power line cycles (PLCs) on the specified channels.Integration time affects the measurement resolution (for better resolution, use a longer integration time) and measurement speed (for faster measurements, use a shorter integration time).If you omit the optional <ch_list> parameter, this command applies to the currently defined scan list.
Parameters
Name Type Range of Values Default Value <PLCs> Discrete 0.02|0.2|1|2|10|20|100|200} MIN = 0.02 PLC, MAX = 200 PLC 1 PLC <ch_list> Channel List One or more channels, as shown:
(@321) - channel 21 on the module in slot 300.
(@221:222) - channels 21 through 22 on the module in slot 200.
(@121:122,222,321:322) - channels 21 and 22 on the module in slot 100, channel 22 on the module in slot 200, and channels 21-22 on the module in slot 300.
Note that the channels must be of the form s21 and s22, where s is the first digit of the slot number.
If you omit the optional <ch_list> parameter, this command applies to the currently defined scan list.
Remarks
- Only the integral number of power line cycles (1, 2, 10, 20, 100, or 200 PLCs) provide normal mode (line frequency noise) rejection.
-
Setting the resolution also sets the integration time for the measurement. The following table shows the relationship between integration time, measurement resolution, number of digits, and number of bits.
Integration Time Resolution Digits Bits 0.02 PLC <0.0001 x Range 4½ Digits 15 0.2 PLC <0.00001 x Range 5½ Digits 18 1 PLC <0.000003 x Range 5½ Digits 20 2 PLC <0.0000022 x Range 6½ Digits 21 10 PLC <0.000001 x Range 6½ Digits 24 20 PLC <0.0000008 x Range 6½ Digits 25 100 PLC <0.0000003 x Range 6½ Digits 26 200 PLC <0.00000022 x Range 6½ Digits 26 - The NPLC command automatically specifies [SENSe:]ZERO:AUTO as OFF for 0.02 to 0.2 PLCs and as ON for 1 PLC or more.
- The specified integration time is used for all measurements on the selected channels. If you have applied Mx+B scaling or have assigned alarms to the selected channel, those measurements are also made using the specified integration time. Measurements taken during the Monitor function also use the specified integration time.
- You can also set the integration time by specifying an aperture time (see [SENSe:]CURRent[:DC]:APERture command). However, note that specifying integration time using NPLCs executes faster and offers better noise rejection characteristics for values of NPLC greater than 1.
- The CONFigure, MEASure?, [SENSe:]CURRent[:DC]:NPLC, [SENSe:]CURRent[:DC]:RESolution commands automatically disable the aperture mode (these commands select an integration time in NPLCs).
- The instrument sets the integration time to 1 PLC after a Factory Reset (*RST command). An Instrument Preset (SYSTem:PRESet command) or Card Reset (SYSTem:CPON command) does not change the setting.
Return Format
The query returns the integration time in the form "+1.00000000E+00" for each channel specified. Multiple responses are separated by commas.
Examples
The following command set the integration time to 0.2 PLCs on channels 21 and 22 in slot 100.
CURR:DC:NPLC 0.2,(@121,122)
The following query returns the integration time settings on channels 21 and 22 in slot 100.
CURR:DC:NPLC? (@121,122)
Typical Response: +2.00000000E-01,+2.00000000E-01
See Also