[SENSe:]TEMPerature:NPLC
[SENSe:]TEMPerature:NPLC
Syntax
[SENSe:]TEMPerature:NPLC {<PLCs>|MIN|MAX}[,(@<ch_list>)]
[SENSe:]TEMPerature: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).
The following table shows which temperature transducers are supported by each of the multiplexer modules.
Module Thermocouple RTD 2-Wire RTD 4-Wire Thermistor 34901A Armature Multiplexer
Yes Yes Yes Yes 34902A Reed Multiplexer Yes Yes Yes Yes 34908A Armature Multiplexer (1-Wire) Not Recommended1 Yes No Yes
1With a one-wire multiplexer, even very small ground currents can introduce substantial measurement error.
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:
(@310) - channel 10 on the module in slot 300.
(@305:310) - channels 05 through 10 on the module in slot 300.
(@202:207,209,302:308) - channels 02 through 07 and 09 on the module in slot 200 and channels 02 through 08 on the module in slot 300.
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 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:]TEMPerature: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?, and [SENSe:]TEMPerature:NPLC commands disable the aperture mode (these commands select an integration time in number of power line cycles).
- 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 03 and 13 in slot 100.
TEMP:NPLC 0.2,(@103,113)
The following query returns the integration time settings on channels 03 and 13 in slot 100.
TEMP:NPLC? (@103,113)
TEMP:APER:ENAB? !Verify that aperture mode is disabled ("0")
Typical Response: +2.00000000E-01,+2.00000000E-01