ITC503 GPIB Read Timeout

[HuMfR33]

Hi Guys

I have been having issues trying to communicate with my Oxford ITC503 temperature controller using the GPIB connection. The device connects and is detected with MAX, but when I try to communicate with it I keep recieving a timeout error upon reading from the device. Writing to it gives no issues and I have been able to set the set point temperature and change the loc/rem state of the device. What is interesting is the when I use the communication tool that comes with MAX, the connection times out but I still recieve a response from the device as can been seen in the image below:

However when I try use the GPIB LabVIEW example, I get no output. All the drivers I have obtained for the ITC503 fail as well. I don't think it is an instrument error as we have 2 such temperature controllers in the lab and both give me the same error. Any assistance that can be provided would be greatly appreciated.

[nyc_(is_out_of_here)]

If the VIs came from Oxford, you should contact them.

[Dennis_Knutson]

A timeout with some data read could indicate that the instrument is not asserting EOI. Older and some newer instruments are not compliant with IEEE-488.2 that requires EOI. If the instrument does not use EOI but instead a terminater such as a carriage return or line feed, you would need to modify the GPIB properties. The manual needs to be referred to.

[HuMfR33]

Thank you for your prompt replies.

Unfortunately the drivers were not written by Oxford Instruments and the ones that they did write were written in LabVIEW 5.1, which is near impossible to find.

I checked the documentation and the ITC503 doesn't assert the EOI line ever and so I think that might be the cause of the timeout. However I have changed all the settings for the GPIB card with regard to terminators and I have had no luck at fixing the problem. Any other ideas? 

I have also considered using RS232 to connect to the device, but when I do I can't read or write to the ITC503.

[NEWKlear]

HuMfR,

You may be able to determine the length of the expected output from the device and have the code auto time out the code after the correct amount of data has been received.  What version of LabVIEW and NI-VISA drivers are you using to control the GPIB bus?

[HuMfR33]

J.Newkirk

I will give that a try as soon as possible. We are using the academic spring 2012 release of LabVIEW 2011 and NI-VISA 5.1.2