IVI DMM Configure Measurement

[Yojtotheworld]

We have a PXI-4070 6.5 digits of resolution DMM. We are trying to configure using iviDMM Configure Measurement in LabVIEW 8.0.

We want to configure the following:

1. 6 1/2 digits of resolution

2. 0-100 ohm range for 4 wire resistance measurement

We cannot use the equivalent NIDMM Configure Measurement.

Does anybody know the values we need to pass into the iviDMM Configure Measurement for:

1. absolute resolution (DBL numeric, not Enaum)

2. Range (DBL)

Any advise greatly appreciated.

A.

[bruno_p]

Hi,

Parameters to pass to the ividmm_ConfigureMeasurements function :
Range value : 100.0 (unit=ohms).
Absolute Resolution : 0.0001 ohms (depends on the range value to get the 6.5digits).

[Aidah]

Hi there,

What is the configuration if i want to measure a resistance value as large as Mega ohms? I tried but it shows the signal out of range.

Regards,
Aidah

[Brian F.]

Hello Aidah.  To measure resistances in the MOhms, you need to use the 2 wire resistance measurement.  The 4 wire resistance measurement is only valid on impedances less than 100 kOhm.  The other key thing to keep in mind is to alter your range when you are making these measurements.  If you are taking a measurement of 1 MOhm and your range is only set for 1kOhm, the signal will be out of range and you will not get a correct reading.  To successfully implement a 2 wire resistance measurement, you must use the top two input terminals on the DMM.  In other words, if you use anything but the top 2 terminals to take a 2 wire resistance measurement, you will not read the correct value.  If you have any additional questions, feel free to ask on this forum or consult the NI Digital Multimeters Help which has a lot of information in it specific to the DMM that you are using.

Brian Fleissner

National Instruments

[Aidah]

Thanks alot for the help!

Regards,
Aidah