lakeshore 325 temperature controller interfacing using GPIB-USB-HS cable

[id47]

Hi,

I am brand new to labview. I have written a VI to read off the temperature data from a Lakeshore model # 325, temperature controller, that calls a SubVI called "Lakeshore ID" within it. However, each time I run the main VI (called "Temp_ctrl") I get an error message "Error 30 occurred at GPIB Write in Lakeshore ID.vi->Temp_ctrl.vi". Also in the SubVI, the inputs for the address and query strings get reversed, each time I run the main VI. The address string becomes "KRDG?" and the query string "12", where 12 is the GPIB address for the controller. This doesnt happen when I run the SubVI by itself. At this point I am not sure if the error is in the SubVI or the Temp_ctrl VI. Thanks in advance for your help!

[Dennis_Knutson]

It's immediately obvious that you have the inputs swapped in your main VI. Always run with Context Help turned on. Pay attention to the tip strip as you move your mouse over the subVI.

Also, you should really use VISA functions for GPIB communication. And, the way you are creating an XY graph is totally confusing to me. First, I don't think it will work at all and all that you really need is a chart.