Trouble generating VISA driver

[ibis]

I’m having trouble developing a driver to allow LabView to interact with a USB device.  I’ve been following the instructions provided in NI’s USB Instrument Control Tutorial (http://zone.ni.com/devzone/cda/tut/p/id/4478).  It seems that I can follow the VISA driver wizard through to driver development and installation.  However, I must not be doing this right since the device is not listed in the Measurement and Automation Explorer and I can’t access it through LabView, though I can see it in the VISA Interactive Control.

Some particulars are, I’m using M.A. ver 4.7.4f0, Labview 7.0, and Win 7, 64 bit.  The device itself is probably not important, but it works as a serial port with a Modbus protocol to communicate with a temperature sensor manufactured by In-Situ.   

Thank you for any suggestions,

Scott

[smercurio_fc]

You usually do not have to do this. You said it "works as a serial port with a Modbus protocol". Then why are you trying to create a USB driver? You should be using the serial port and the Modbus library.

Also, LabVIEW 7 is not supported on Windows 7. And, in order to have a version of NI-VISA that runs on Windows 7, that version of VISA will not support LabVIEW 7.

[ibis]

Well, I'm trying to write a USB driver since the VISA resource I need is listed as:

USB0::0x0403::0x6001::10FRLW5P::RAW

The serial port is avalible through the USB device, so I figured I needed to have a USB driver to access this.  The LV 7 Win 7 and driver wizard compatability might be an issue, though.  Is the same compatability issue true for Win Vista?

[smercurio_fc]

Yes, the LabVIEW 7 issue will exist with Vista as well.

In order to use a device in USB RAW you need to know a LOT of detail about the communication protocol. Vendors rarely give this information out. Is there a DLL they provide? If so, you can use that using Call Library Function Node. What is the device you are using? Do you have a link to the manufacturer's web page? Some documentation?

[ibis]

It would be great if I could use the existing device driver for labview use.  How does that work?  As for the communications protocol, they use Modbus.  The vendor is In-Situ, and they will let me ask low level details of their engineers in order for me to get this working.  

So, are there 2 ways to go?  1) somehow use the existing device driver for windows, or 2) use the driver developement wizard to create a driver for a RAW device, provided I know details of the protocol used.  

You suggested that the second approach would likely lead to compatability issues accross differing software versions.  Is that also a limitation with appraoch 1?

Thanks,

Scott

[Dennis_Knutson]

If they are using serial modbus, then use that. There is a LabVIEW library for that.

[ibis]

I have the Modbus library and when I use it, the device does not initialze.

Moreover, I have also gone through the process whereby I uninstall LV 7 and all NI software, download and install the latest Measurement and Automation software from NI with the latest VISA device driver wizard, and run it to develope a driver for this device specifically for Win 7.  This all looks like it executes just fine.  However, the device still is not shown in the Measurement and Automation Explorer.

Any ideas what I should do differently, or does a device not have to be listed in the MA Explorer to be usable in LV?

Thanks

[Intaris · Accepted solution]

A USB serial device will show up in Windows as a classic serial port.  You need NOTHING from LV to be able to use this as a standard serial port.  Forget USB RAW completely.  install the vendor's drivers and be done with it.

And I'm saying this as author of a few USB RAW nuggets.

Shane.

[Kira_T]

Hey Ibis,

How does the device appear in your Windows Device Manager?  Have you checked to see that your NI Device loader has started?  To do this got to Control Panel>Administrative Tools>Services>NIDevice Loader and check to make sure that the status of the service is Started.  When this is not started your devices can not be recognized in Measurement & Automation Explorer.  Did you install a different version of LabVIEW when you uninstalled the others?

Kira T