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Mantaining Temperature with Lakeshore Temperature Controller 331

We're using labview 7.0 to monitor the pressure and temperature of a sample. For temperature, we're using a Lakeshore 331 Temperature Controller. Many of our experiments require our sample to be kept at a constant temperature. The temperature controller has two thermometers, A and B. A is right next to the sample while B is next to our cryostat. Right now, we're choosing a setpoint for A, then watching B drift upwards and once it gets beyond 0.2K what we we want, we lower the setpoint by 0.2K so that the sample gets back to within where we want it. Initially, this requires manually resetting the setpoint every 20 minutes or so. As time goes on, that times becomes longer but still requires manually choosing a setpoint every now and again. Ideally, we'd like to be able to automate the setpoint process so that we can run our experiment overnight and over weekends. Can anybody help with this? I've attached the VI we use to monitor pressure and temperature. I'm not sure if we're set up to control the Lakeshore 331 as opposed to just reading it, so any information on that would be very helpful.
Thanks
 
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Message 1 of 16
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Hi Sufun,

 

Yes, it appears that you are just set up to read from the Lakeshore 331 now, not to control it.  

 

Can you confirm that you have this driver installed or another?

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=E3B19B3E9164659CE034080020E748...

 

The above mentions that it includes some example Vis for how to control it which might help you under Getting Started.  If that doesn't help, please contact the manufacturer to help you further to interface with the device.

 

Sincerely,

 

Bogdan Buricea

Applications Engineering

National Instruments

Bogdan Buricea
Applications Engineer
National Instruments
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We've installed Labview 2010 on another computer to take advantage of the drivers. However, the computer doesn't have a DAQ device. Is there any way to control the temperature without one? Our other computer has a PCI-6014, which we could move over, but if there's a way to simply control the temperature without a DAQ that would be very helpful.

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Hello Sufun,

 

How do you communicate with your Temperature Controller?

Mr.O
Applications Engineer
National Instruments
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Message 4 of 16
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The computer that runs the VI I posted that reads the temperature has a PCI-6014 but that runs Labview 7, for which I couldn't find drivers. I just connected it to a computer running Labview 2010 using a RSC-232 cable through the serial port.

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I ran one of the example VI's and got an error.

 

Error -1073807339 occurred at VISA Read in Lake Shore Cryotronics 331.lvlib:Initialize.vi->Lake Shore Cryotronics 331 Application Temperature Controller.vi

VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed.

 

The second line also come up when I try to query the Temperature controller in VISA Test Panel with a command like, for example, "*IDN?" which is supposed to an identification string. When I write the string, I get a return count (of X bytes) and no error message. My serial port is also definitely working, at least according to the test posted on NI's website.

 

 

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What version of VISA are you using?

Mr.O
Applications Engineer
National Instruments
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I have VISA 5.0. I just tried writing some commands to control the Setpoint and Heater Range through VISA and couldn't see any change on the controller's front panel. I also tried switching to Remote mode but that didn't make a difference.

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Try incrementing the timeout for the VISA using the VISA Set Timeout.

Mr.O
Applications Engineer
National Instruments
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Message 9 of 16
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I've tried incrementing the timeout in VISA test panel and still get a timeout error. In the example program in the driver, I also get the following error:

 

Error -1073807346 occurred at VISA Open in Lake Shore Cryotronics 331.lvlib:Initialize.vi->Lake Shore Cryotronics 331 Application Temperature Controller.vi

VISA:  (Hex 0xBFFF000E) The given session or object reference is invalid.

 

In the visa test panel view attributes tab, the following is also the only one in red:

Attribtue - Is Port Connected

VISA Atrribute Name - VI_ATTR_ASRL_CONNECTED

Current Value -

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