LabVIEW causing unstable readout

[JBrown97]

Hi all

I'm measuring the temperature of my sample using a Lakeshore 331S. Without LabVIEW the temp reading on the lakeshore is stable, and in agreement with pyrometer measurements. When I run the VI the output from the VI gives a very unstable temperature, fluctuating up to about 3 kelvin. The output on the Lakeshore also becomes unstable, but it seems to fluctuate even more (roughly 10 kelvin). When I stop running the VI the output on the lakeshore immediately stabilizes again.

I'm testing these connections out on the example VI's available from the Lakeshore 331S drivers found online (http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=7094CC81B2146DD9E04400144FB7D2...). In particular I'm using the "application temperature controller" VI.  I'm running LabVIEW 2015 so I have 2015 driver.

I'm reading on a k-type thermocouple and my lakeshore is connected via an RSC-232c null modem cable

Thanks!

[santo_13 · Accepted solution]

Definitely seems like the settings are completely different when you run the VI vs when running standalone. Please verify if all the configurations match.