[SENSe:]FRESistance:RESolution
Syntax
[SENSe:]FRESistance:RESolution {<resolution>|MIN|MAX|DEF} [, (@<ch_list>)]
[SENSe:]FRESistance:RESolution? [{(@<ch_list>)|MIN|MAX}]
Description
This command selects the measurement resolution for 4-wire resistance measurements on the specified channels. Specify the resolution in the same units as the selected measurement function, not in number of digits. If you omit the optional <ch_list> parameter, this command applies to the internal DMM, independent of any channels or a scan list.
Used With:
34921A Armature Multiplexer
34922A Armature Multiplexer
34923A Reed Multiplexer (differential mode only)
34924A Reed Multiplexer
34925A FET Multiplexer (differential mode only)
Parameters
|
Name |
Type |
Range of Values |
Default Value |
|
<resolution> |
Numeric |
Desired resolution in ohms. |
0.000003 x Range (1 PLC) |
|
<ch_list> |
Numeric |
One or more channels in the form (@sccc). |
If <ch_list> is omitted, this command applies to the internal DMM. |
Remarks
For 4-wire resistance measurements, the instrument automatically pairs channel n in Bank 1 with channel n+20 in Bank 2 (34921A, 34923A, 34925A) or n+35 (34922A, 34924A) to provide the source and sense connections. For example, make the source connections to the HI and LO terminals on channel 2 in Bank 1 and the sense connections to the HI and LO terminals on channel 22 (or 37) in Bank 2. Specify the paired channel in Bank 1 (source) as the <ch_list> channel (channels in Bank 2 are not allowed in the <ch_list>).
Four-wire measurements are not allowed on the multiplexer modules configured for the single-ended mode (see SYSTem:MODule:WIRE:MODE command).
For the <resolution> parameter, you can substitute MIN or MAX for a numeric value. MIN selects the smallest value accepted, which gives the highest resolution; MAX selects the largest value accepted, which gives the least resolution.
If you omit the optional <ch_list> parameter, the configuration applies to the internal DMM, independent of any channels or a scan list (any existing scan list is not redefined). An error is generated if the internal DMM is not installed or is disabled.
Since 2-wire and 4-wire resistance are related functions, changing a measurement parameter for one function will also change the corresponding parameter for the other function (see [SENSe:]RESistance:RESolution command).
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 |
4 |
15 |
|
0.2 PLC |
< 0.00001 x Range |
5 |
18 |
|
1 PLC |
< 0.000003 x Range |
5 |
20 |
|
2 PLC |
< 0.0000022 x Range |
6 |
21 |
|
10 PLC |
< 0.000001 x Range |
6 |
24 |
|
20 PLC |
< 0.0000008 x Range |
6 |
25 |
|
100 PLC |
< 0.0000003 x Range |
6 |
26 |
|
200 PLC |
< 0.00000022 x Range |
6 |
26 |
You can also set the integration time by specifying an aperture time (see [SENSe:]FRESistance: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:]FRESistance:NPLC, and [SENSe:]FRESistance:RESolution commands disable the aperture time mode (these commands select an integration time in number of power line cycles). You can use the [SENSe:]FRESistance:APERture:ENABled? command to query whether the aperture mode is currently enabled or disabled.
The instrument sets the resolution 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 command returns the resolution in the form "+1.00000000E+02" for each channel specified. Multiple responses are separated by commas. Note that if the aperture mode is currently enabled (see [SENSe:]FRESistance:APERture:ENABled? command), the value returned will represent the previous value specified, not the actual integration time.
Examples
The following command sets the measurement resolution to 100Ω on channels 3 and 13 in slot 1. For this 4-wire measurement, the instrument automatically pairs these channels in Bank 1 with the corresponding channels in Bank 2.
FRES:RES 100,(@1003,1013)
The following query returns the resolution selected on channels 3 and 13 in slot 1.
FRES:RES? (@1003,1013)
FRES:APER:ENAB? !Verify
that aperture mode is disabled ("0")
|
Typical Response: |
+1.00000000E+02,+1.00000000E+02 |