When using IVI class drivers how do you use logical name in the Block diagram?

[Newenglandguy_LV]

When using IVI class drivers how do you use logical name in the Block diagram?  Also, how do you pass the address to them?  Do you still use the the address in the Resource Name, or do you use the logical name?  I can't find clear documentation on that.

Speaking of which, does anyone have a recommendation that focuses on test instrumentation and it's control, using LabVIEW?

[Omar_II]

Have you configured your IVI instruments in MAX with the Logical Name you wish to use.

The address is configured in MAX.

The logical name will then be listed in the VISA ref drop down or you could use a string of your logical name.

See these links

http://zone.ni.com/devzone/cda/tut/p/id/4558

http://zone.ni.com/devzone/cda/tut/p/id/3377

[Newenglandguy_LV]

Omar - thanks, your comments and those two links has been a huge help. I'm getting closer to things working, but I haven't figured out how the address gets configured.  You indicate you do it in MAX, but I do not see them doing anything with the address in the second link's example.  I'm still working it.

[Omar_II]

Address? What kind of address?

What bus are you using? GPIB? USB? Eithernet? PXI Chassis? PCI? Serial Comport? etc.

In MAX, does your device show up with it's normal addressing (non IVI)?

[Omar_II]

Using Measurement & Automation Explorer to Configure Your IVI System

[djpritchard]

Omar - thanks for those links - I find them very informational.  From whe I gather from reading those links - I'm not at work so I can try some things.  It seems to force the hard wiring of addresses to logical names, and I was hoping to work a scheme where I could run a routine to check instruments on the bus and then send the appropriate address in to the sub VI for that instrument.

[Omar_II]

Searching the busses to find your instruments is very do-able, but you need to work at the bus level and not at the IVI level. Use the VISA Find Devices function to locate devices on busses like GPIB, USB, and Serial. Use “*IDN?” command to locate the device you are looking for if they are SCPI compatible or some other technique unique to your device.  Use niModInst for NI PXI and PCI modular instrument like NI-SCOPE, NI-DMM, NI-SWITCH etc. For non-NI PCI or PXI devices, I use MS DevCon utility calling it via System Exe to find the devices. There are even TCP/IP function to help locate Ethernet devices. If the code is designed right, you can search more than type of bus and find your instrument if it is switch from GPIB to USB.

This is a technique I use regularly and is the standard for addressing all our instruments. I don’t think I have a any instrument code that is hard wired with the instruments address. This is important with USB devices where the addressing contains the device’s serial number. So when the device is swapped out for calibration with a different device, my test code can automatically update the USB address string with the new serial number. Extra care has to be taken if you have more than one of the same device.

This system works if only the addressing of the same device is changing, but does not always work if the manufacture or model of the instrument is likely to change. That is what IVI drives are for. To be able to swap a DMM of one model, manufacture and device driver with another DMM of another model, manufacture and device driver without having to change your test code. Even if it is a compiled EXE. But these changes or done manually in MAX, external to your test code.

I have had limited success using the MAX Configuration VI to change instrument aliases in MAX. This was an external utility to aid in swapping out 6 identical USB power supplies and to assign the correct alias to the correct serial number of the supplies. It envoled editing an INI file and then loading the INI file into MAX.

Hope this helps.