Uninstalling LabVIEW 8.0

[tcsieng]

I have installed LabVIEW 8.0 and encountered a problem with controling a Keithley 40-SR01 swtich relay through a 7002 swich mainframe.   I've down loaded and install a new instrument library file, KE7002.llb driver.  Unfortunately, this did not correct the problem.  The only option that I'm left with is to unstall LabVIEW 8.0 and return to LabVIEW 7.1.  How do I save backwards from v8.0 to 7.1?  Can I save backwards?

[AnalogKid2DigitalMan]

File/Save As/Previous version or something to that effect will save your 8.0 code to 7.1

[Robert M]

What was the problem with LabVIEW 8.0?  I would be very curious to know what works in LabVIEW 7.1 but not in 8.0.

If you do want to revert to 7.1, it may be easier to download the 7.1 version of the instrument driver, unless there isn't one or you need to convert code you have written as well.  In this case you can use "File >> Save for Previous Version".

[tcsieng]

Robert ,

LabVIEW is used to controll a Tektronix CSA8000 digital oscilloscope and a Keithley 7002 microwave switch mainframe.  This system is used for high-speed electrical testing and operates in either single-ened or differential modes.  When LabVIEW 8.0 was installed the ability to test in differential mode was lost, the system ran as if it were single ended.   It's unclear exactly were the problem was/is but it was determined that the program could not read the differential memory locations however, it read the the single-ended memory locations in differential mode.  Could this be a GPIB problem? A VISA problem?  Even after installing an updated KE7002.llb file the problem was still present.   Therefore, the need to save backwards.  However, after further investigation it was learned that the original test program was developed using LabVIEW 7.0 and not 7.1 as originally thought.  Would that have made a difference?  

A second problem was the ability to generate the test report had changed.  Meaning that the sub vi that captures the indicator as a jpeg, would only captured a portion of that indicator.  There was some kind of change in the screen snap that caused that error.  Therefore, the need to revert back to v7.0.  Again, would going from 7.0 to 8.0 be the problem?

The test system was to be implemented into a production enviroment at the end of January 2006 and has sat idle because of the differential problem.  However, there was a work around to revert back to 7.0, and that was implemented just this week.

So the question really is:  Was going from v7.0 to v8.0 too large of a jump or is there something else going on?  

I would appreciate any help in better understanding the problem so v8.0 can be installed. 

Thank you.

[Dennis_Knutson]

Is it the Keithley or scope that is supposed to be in differential mode? If so, can you go into MAX and issue the command there to change it? If you can change it manually, then you probably don't have a problem with either VISA or GPIB. In the section of program where the mode is supposed to be set, are you using any local variables? Can you run just that section of code and see it it works. One thing that happens when you upgrade is that the program get's re-compiled. Local variables are subject to race conditions and it's possible that the re-compilation exposed one that you never saw before. The execution time of the program is also probably a bit different. You may have exposed a problem with timing in the order that you send commands. Could it be that the instrument is just not ready when you issue the mode command now? Can you post the section of code that does the mode change?

[tcsieng]

Dennis,

Q: Is it the Keithley or scope that is supposed to be in differential mode?  A: The CSA8000 is what is in differential mode.  When the program is activated the scope sets up and functions as it should except that the Keithley switch does not operate as a 1x48 multiplexer, it operates as a 1x96 multiplexer so the scope does not truely operate in differential mode.  Q: Can you post the section of code that does the mode change?  A: That would be a huge file however, prehaps I can give you a better explanation.  The setups, wether differential or single-ended, are separate setups that the user selects.  Based on that mode selection, the program recalls the respective scope setup and the first memory location of the Keithley switch is called through an initialization file - single-ended is location 1 and differential is location 100.   In the differential case the scope sets up in differential mode, but the Keithley switch does not operate as a 1x48 multiplexer.  It will switch 48 times in a 1X96 configuration.  That leads me to believe that the problem may be related to the GPIB - but I've been wrong before.  

The big challenge for me is that the tester is now off-site and I don't readily have available access to it.