bridge offset calibration vi error -200077 after upgrade

[Measuror]

Hi all,

after upgrading from LabView 8.2.1 to LabView 8.6 the DAQmx Perform Bridge Offset Nulling Calibration.vi that i automatically run at start in my VIs exits with error -200077: requested value of samples per channel is 1 but valid values start from 2. I didn't change anything in the VIs between the upgrade.

I'm using cDAQ-9172 with NI 9219 bridge measurements module. When using MAX or setting up channels in DAQassistent measuring works fine, but using the bridge calibration vi does not.

Any help is appreciated since for now to keep on measuring i have to skip the bridge offset calibration which is not good.

Greetings,

The Measuror

[StefanA]

Hey Measuror,

my first thought is that there might be a problem with your calibration data.

Please habe a look into the Knowledge Base and check if your data is in Range.

KB 3UKG06X1

Regards,

Stefan

[StefanA]

Message Edited by StefanA on 08-21-2009 11:10 AM

[Brad_K]

Hi Measuror,

Could you post more information about your application? Does it use DAQmx Timing (Sample Clock).vi for the NI 9219 task? If so, what values does it pass to this VI? Does it set any additional DAQmx properties? How many channels are you measuring?
Could you try the shipping example Cont Acq Strain Samples (with Calibration).vi with the "Do Strain Null?" control set to true and see if that gives the same result?

Also, what version of NI-DAQmx are you using?

Brad

[Measuror]

Hi Brad and Stefan,

thanks for your answers so far.

@Stefan:

As i wrote, everything works fine when running the configured task in DAQAssistant. There i set sample rate = 2 and also number of samples to aquire = 2. I also tried to configure those two parameters externally by applying constants to the appropriate inputs of the DAQAssistant.vi but still bridge offset nulling doesn't work.

@Brad:

I simply use DAQAssistant for setting up one task including several channels: in one VI i have  two strain gauges in quarter bridge II config and a force sensor configured as full bridge voltage sensor; in another VI i have a strain gauge as quarter bridge II and a Pt1000 temperature sensor.Both VIs stop with the same error (see my first post). I don't use any other VIs for hardware config.

I will try the example VI you mentioned on monday 'cause for this week i'm done with work .

The DAQmx version i'm using now is 8.9.5 (installed two days ago). I can't remember the DAQmx version i used before upgrading. But as i wrote in the first post, with LabView 8.2.1 everything worked fine.

Edit: I forgot to mention that when i remove the temperature channel from the first VI in DAQAssistant it runs without errors. I use the parameter skip channels that cannot be calibrated though it should be no difference.

Have a nice weekend,

Measuror

Message Edited by Measuror on 08-21-2009 12:48 PM

[Measuror]

Hey Brad,

I tried the example VI as you suggested and it works (calibration works too). I noticed though, that in the example the hardware is set up using single VIs. As I wrote earlier I'm using DAQAssistent.vi for setting hardware parameters. Could this be the trick?

Attached you find my two VIs that don't work with calibration, but when I remove the calibration VI everything works fine. Maybe you find the time to look over them and hopefully find out what's wrong.

For now I'm sticking to using the two VIs without bridge offset calibration, since the offset nulling is done by software only anyway for the 9219, right? I can do that step during data analysis so it's no great loss, but it surely is inconvenient.

If I have the time i'll try rebuilding the two VIs with the manual hardware setup but for now I have to keep on measuring.

Have a nice day,

Measuror