Bug: no 3FFA2001 warning PXI-4065

[JÞB]

Config Data:

LabVIEW 2010f4

NI-DMM 3.0.3

DAQmx 9.2.2

Hardware:

PXI-1044 Win XP

PXI-4065

Neither IviDmm Read.vi nor IviDmm Read Mutlipoint [MP].vi return the expected 3FFA2001 warning on a overange condition. 

Funny, Last week I was running a USB-4065 on a Win7 PC with LabVIEW 1010f4, NI-DMM3.0.3 and DAQmx 9.2.2 and the USB-4056 DOES return these warnings. 

Ref Help for either vi.

2 If an overrange condition occurs, the corresponding Reading Array element contains an IEEE-defined NaN (Not a Number) value and the VI returns the IVIDMM_WARN_OVER_RANGE (0x3FFA2001) warning code

QUESTION: how does IviDmm Is Over-Range.vi identify the over-range condition?  does it mearly depend on a NaN at "measurement value" or does it query the instrument?

[JÞB]

Amplification and correction.

 Bug: no 3FFA2001 warning PXI-4065 exists only with the IviDmm vis  NI DMM correctly reports the warning.  Looking at the source for what I was working with last week I was using the NI DMM IVI drivers.

Why there should be a disconnect between the DMM>IviDmm and NIDMM classes of IVI sessions is beyond me.  Especially when the documentation of the overrange behavior is identical.

[GarPar]

Hey Jeff-

     Here is a great KnowledgeBase article that will help to explain what is going on.  The long and short of it is that depending on the range/device, you may or may not get over range warnings or NaN returned.  You are likely seeing this variation between the different driver sessions.

     I hope this helps.  Have a great day!

[JÞB]

---

@GarPar wrote:

Hey Jeff-

     Here is a great KnowledgeBase article that will help to explain what is going on.  The long and short of it is that depending on the range/device, you may or may not get over range warnings or NaN returned.  You are likely seeing this variation between the different driver sessions.

     I hope this helps.  Have a great day!

---

Nice KB article thanks.  Can you address the differance between the IviDMM and NIDmm drivers?  Specifically why the over-range warning code is not thrown by the iviDmm session but is thrown by the NI Dmm session.

[Steven_K.]

Hi Jeff,

Have you enabled range checking in the IviDMM driver? There is a setting in Measurement & Automation Explorer to enable it.

[JÞB]

Thanks for the reply- Yes, range checking is enabled however, Range checking applies to settings (error if an applied setting is out of range) and not to over-range readings.  readings that excede the set range like, a 1Mohm resistance on a 10K ohm scale, should result in a Reading of NaN and a warning 3FFA2001.  this combination of outputs does occur with the NIDMM driver but not with the IviDmm driver.

[Steven_K.]

Hi Jeff,

Sorry for the late reply. I spoke with R&D and they can confirm that they were able to reproduce what you have seen. This isn't expected behavior. One way around this is using the IviDmm Is Over-Range.vi and look for the boolean output.

[JÞB]

If you have a CAR please post it so we can see it from the bug thread

[Steven_K.]

Hi Jeff,

The CAR number is 284075.