NI Instrument simulator 2.0 not compartible with Instrument I/O assistant express VI?

[Mbdeck]

 Hi Justin E,

I'm having problems again with the simulator. This time, the Simulator does not recognize a device alias.  I'm working in gpib configuration in multi-instrument mode comprising three devices.  I designated the multimeter or "instrument 2" with an alias ("devsim" in MAX) but when I select this alias from the "select an instrument" pull-down menu on the Instrument assistant express VI and click "run this step" nothing happens.

On the other hand when I put the gpib "instrument discriptor" ie gpib[board]::PAD::[INSTR], it works fine. I don't understand why?.  I looked at a knowledge base on ni.com and repeated their procedure and it still didn't work.

http://digital.ni.com/public.nsf/allkb/C063FA3D7C71CE80862569B60074F4A6?OpenDocument 

Can you try it with the same type of simualtor and see if you run into the same problem? Also I'm using a gpib-usb controller.  NI gpib-usb-B from National instruments but I don't think this is the problem but I just thought I'd mention it just in case.

[Justin_E]

Hey Mbdeck,

I set up the Instrument Simulator 2.0, gave it a VISA Alias in MAX, opened up an Instrument I/O Assistant, and was able to successfully send/receive a *IDN? command to the simulator. It seems like if you're still able to select the instrument descriptor in the pull-down menu, then the VISA Alias was probably not saved for that device. 

[Mbdeck]

Justin E,

I think did exactly what you just wrote and it still didn't work for me. Could you please outline step by step what you did?. I repeated the set up a number of times in MAX and still didn't get a response with I/O assistant. Perhaps I may be missing a detail in the process.

[Justin_E]

Mbdeck,

I've attached a screenshot of my Measurement and Automation Explorer window as I'm setting up the VISA Alias. These next steps are assuming that your GPIB controller card is configured and set up correctly, and that you're using the latest versions of NI-VISA and NI-488.2. The first thing I did was connect my Instrument Simulator 2.0 to my PCI-GPIB card. Next, I powered on my simulator, scanned for instruments in MAX, and saw Instrument 0 appear. I then typed in a VISA Alias in the VISA Properties tab ("dev1"), and saved that Alias. I opened up LabVIEW, set an Instrument I/O Assistant Express VI on the block diagram, and selected "dev1" for my instrument. Finally, I create a Write and a Read and Parse step, and wrote *IDN? to the device. The Read and Parse step successfully read the Instrument Simulator's information.

[Mbdeck]

Hi Justin E,

I followed your directions and I'm still having problems with my device. I still can't designate a device alias. I'm suspecting that the problem is from my GPIB-USB controller card. I have the GPIB-USB-B controller. It recognizes only the instrument descriptor but not the alias. My NI 488.2 is of the 2.46 version. I think everthing was configured correctly but the card might be the problem. Can you try this same procedure with GPIB-USB-B controller card and see what you get. If you end up having the same problem that I'm currently experiencing, can you see if their is some kind of driver upgrade that could help rectify it.

Thanks

[Justin_E]

Hey Mbdeck,

I obtained a GPIB-USB-B, hooked it up to the instrument simulator, and was able to designate a device alias and communicate using the I/O Assistant using the same method I used before. One thing I would recommend is upgrading your NI-488.2 driver to the latest version (version 2.7). This version is fully compatible with the GPIB-USB-B device and with LabVIEW 8.2, so you shouldn't run into any new issues when upgrading. The 488.2 driver downloads can be found here : https://www.ni.com/en/support/downloads/drivers/download.ni-488-2.html

Try upgrading your driver and see if you can set/use aliases.

If this doesn't work, then we have a couple of other things we can try. First, in the Instrument I/O Assistant, under the "Select an instrument" drop-down menu select your device, then click the Properties button to the right of that menu. This should open up a screen that looks similar to the configuration screen in MAX. If you click on VISA Properties, do you see the alias you designated for this device listed? 

Another thing I want you to try is to place a VISA Write function on your block diagram. Right click on the VISA Resource Name terminal, and select Create->Constant. This will introduce a VISA resource name constant, where you can select a VISA resource. Right click on this constant, and go to I/O Name Filtering... Under the General tab, make sure that the "Show Aliases" box is checked. Now, if you expand the VISA resource name constant, can you see your alias?

[Mbdeck]

Hi Justin E,

I downloaded the 488.2 V2.7 and my device has now started working. I can now designate an alias that is recognized by the Instrument assistant express VI.  One other question I have is whether I can use my GPIB-USB-B on a pc with windows Vista?. 

Thanks again Justin.

[Justin_E]

Mbdeck,

Glad to hear that it's working! Yes, you can use your GPIB-USB-B on a pc with Vista.

[Mbdeck]

Hi Justin E,

I built a VI that would communicate with the instrument simulator through instrument drivers but I'm getting error messages each time I run the VI.  Here is the VI description:

"In this exercise, the objective is to build a VI that uses the DevSim instrument driver VIs to acquire and plot voltages. Complete the following steps to build a VI that acquires a DC voltage measurement from the NI Instrument Simulator once every second and plots it in a waveform chart until you click a button. As each value is acquired, the VI compares it with the previous minimum and maximum values. The VI calculates and displays the minimum and maximum values continuously on the front panel"

 When I run the VI, I get this error message below:

Error -1073807339 occurred at VISA Read in NI DEVSIM Read.vi->NI DEVSIM Measure DC Voltage.vi->Voltage Monitor.vi

 Possible reason(s):

 VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed.

I've attached my code and I'll appreciate your help here. I'm looking forward to your reply.

Thanks

[Justin_E]

Hey,

I had some troubles opening the VI you posted. The naming of various VIs in your program differ from the naming of the ones in the DevSim driver that I have. Did you get you DevSim driver from the link that NathanT posted earlier? I've re-attached the VI replacing the functions that were named differently to ones straight from the DevSim library (labeled National Instrument Device Simulator in LabVIEW). I ran this VI with Instrument Simulator 2.0, and it ran fine without the timeout error. Try opening my VI and see if it works on your simulator.