Dear All, I am posting this question because I am completely stuck in what should be a very simple program, merely a modification of the example one available in the drivers for the HP4140B pA meter / DC voltage source (available online at: http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=E3B19B3E92C3659CE034080020E74861). I must clarify that I have already had issues with this legacy equipment drivers in the past, and I finally had to use LabVIEW 7.1 (instead of LabVIEW 8.6), so there is a certain underlying difficulty... The idea is adding a shut-off current to the "HP4140B Example (current vs voltage).vi" program, so that when a certain current value is reached, the measurements are stopped and the voltage goes back to 0V (so that the sample is not burnt when its conductivity increases). All the issues must come from the "HP4140B Read Wave Meas.vi" subVI, which is where I have made changes and where the execution has problems (when I check the highlighted mode), usually because of a timeout error [Please note that the example program runs nicely]. I have tried two approaches: (1) Since the output from the Read Wave Meas subVI is an array, it's more complicated to compare single values and react quickly so as to avoid burning the sample, so I just removed the indexing of the inner subVI loop (getting just double-type current and voltage values at the interface, instead of arrays), added a greater than block (with a control value), and then put back the subVI and the new blocks in another do-while to generate the arrays [please find enclosed the main program and the modified subVI below]. (2) The alternative that I also checked was making no changes in the main vi and simply adding the greater-than block inside the do-while loop of the Read Wave Meas subVI: by adding an AND gate, I could check that both the pre-existent condition and the new one were satisfied so that the loop continued. Despite the fact that it's a small change, the system doesn't work either. I would really appreciate any suggestions on alternative ways or any feedback on why the aforementioned two don't work!!! Regards, Pablo

LabVIEW

Issues with I-V measurement (including a shut-off current) and HP4140B

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To make a pop-up window from a subVI you go to VI Properties (pop-up on the icon form the front panel). Under the category: Window Appearance select Customize... In the dialog which appears check "Show front panel when called" and "Close afterwards if orignally closed." Save the subVI and close its windows. When you run the main VI, the subVI front panel will open and the user can interact with it until it finishes at which time it will close. If you do this you should also uncheck several other buttons like Show Abort and Allow user to close and probably some others.

Lynn

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LabVIEW

Issues with I-V measurement (including a shut-off current) and HP4140B

Re: Issues with I-V measurement (including a shut-off current) and HP4140B