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USBTMC Gaussmeter

Hey everybody! Smiley Very Happy
I'm a total LabView newbie, so I've got a feeling that my question is probably answered in about a dozen places.  All help is appreciated, and please feel free to point me to other threads/tutorials/examples.
My company is using LabView 8.2.1 and a coworker has asked me to create a stepper motor that will rotate our device to next to a gaussmeter's probe.  The motor interface we can takle later, as for right now I'm trying to figure out the gaussmeter.  I'll be using a FW Bell 5180 hand held.  It's a USBTMC device, so it's commands are pretty straightforward.  I need to pass it strings and then read it's responses. 
The problem I'm having now is communication.  I know the device can communicate to my PC b/c the software that came with it works (displays current readings on the FW Bell software included with the device), but I cannot seem to get it to show up on NI-MAX.  I've not gone so far as creating my own USB RAW driver as described here:
because, I believe that I don't need to according to section 3.  I guess my specific question is, how do I get my gaussmeter to 1. Show up in NI-MAX and 2. Get my gaussmeter to show up as an option under the VISA resource name dropdown menu on the Front Panel.
I'll try to answer any questions... 
Thanks again!
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Message 1 of 11
It all depends on the software support you can get from the vendor. Do they offer any sort of drivers or port emulators for talking to the things from a programming environment? Sometime you can get software that makes the device look like it's connected to a serial port. Sometimes they have their own DLL that you can call.

I just checked the FW Bell website and according to the 5100 series manual (pages 4-1 and following) talking to this device should be a snap. All you have to do is download the interface software from their website.


Message Edited by mikeporter on 07-23-2007 06:26 PM

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Message 2 of 11
I hope it'll be a snap!  Maybe you can help me further, Mike...
I've installed the software that came with the 5180, and when you fire it up it does communicate through its own little GUI.  I'm sure you know this already, but looking to do this through the LabView environment.  I guess I'm looking for a more remedial answer to my communication problem... 
I've basically built the block diagram in the example of Figure 8 of the above NI tutorial "USB Instrument Control Tutorial", hoping that the *IDN? string that I pass to the gaussmeter will return the MFGR inform.  Unfortunately, the gaussmeter does not show up as a VISA resource on the front panel.  I imagine that I need to do some tutorials on building VIs that contain VISA... any suggestions?  I've got no idea how to make the 5810 meter show up as an option there.
The whole "Call Library Function Node" is a mystery to me.  I tried to point the node to a couple DLL files that were installed on my PC after installing the gaussmeter, but apparently I need to specify what function I'm attempting to call.  Is this different than *IDN?  Honestly, I don't even know how I'd configure the block within a block diagram if I got it to connect to the proper DLL.
Thanks again for any suggestions.
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Message 3 of 11
The inference that I drew from the manual is that there is an additional software package that needs to be installed, and that you download it from their website. If you can't find it call the vendor tomorrow and ask where the software is at. Once that is installed, it should show up in the Windows Device Manager as a serial port.


PS: doesn't look like you have to worry about DLLs this time...

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Message 4 of 11
A USBTMC device will not show up in the system as a serial port. It should show up in MAX as USBTMC. A USBTMC is designed to emulate a GPIB device more than a serial port. Did you do a refresh in MAX after installing the driver? What version of VISA do you have installed?
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I've installed the drivers and utility software that came with the Data CD of the FW Bell device.  When I download the additional software from their website and run the .msi file, there's an error stating that "another version of this product is already installed".  I'm assuming that there's no real difference between the two, but I'll try to remove the one and install the other if nothing else works.

The gaussmeter does show up in Windows Device Manager.  It pops up under an icon that looks like the USB icon, but it is labeled "LibUSB-Win32 Devices" and is not under the "USB controllers" folder.  I plan to investigate LibUSB this afternoon here on and via google...


Unfortunately, a refresh of MAX does not show any new devices (USBTMC or GPIB or Serial) even when I know it is working and connected.  I looked up the version of "NI-VISA interactive control" that came with my labview software and it is 4.1-implementation and 4.0-specification  (this is the first time i've launched this program and I intent to look into the help file to see if there are any answers in there).
Are there any examples or more detailed tutorials that would demonstrate how to link up a USBTMC device so that labView will recognize it as GPIB?


Again, all help is very much appreciated!

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Message 6 of 11
I wish I had a USBTMC instrument available but I don't and I can't even find a copy of the inf file that came with one. All that I have now are several USB RAW. Have you looked at the inf file that came with the instrument? I think the class specification should be in there.
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Message 7 of 11
Not sure if this will help, but here's the fwb5100.inf file, copied and pasted directly (the only .inf included in the file folder):
Signature = "$Chicago$"
provider  = %manufacturer%
DriverVer = 08/27/2006,
CatalogFile =
CatalogFile.NT =
CatalogFile.NTAMD64 =
Class = LibUsbDevices
ClassGUID = {EB781AAF-9C70-4523-A5DF-642A87ECA567}
HKR,,,,"LibUSB-Win32 Devices"
; Files
1 = "Libusb-Win32 Driver Installation Disk",,
libusb0.sys = 1,,
libusb0.dll = 1,,
libusb0_x64.sys = 1,,
libusb0_x64.dll = 1,,
libusb_files_sys = 10,system32\drivers
libusb_files_sys_x64 = 10,system32\drivers
libusb_files_dll = 10,system32
libusb_files_dll_wow64 = 10,syswow64
libusb_files_dll_x64 = 10,system32
; Device driver
CopyFiles = libusb_files_sys, libusb_files_dll
AddReg    = libusb_add_reg
CopyFiles = libusb_files_sys, libusb_files_dll
CopyFiles = libusb_files_sys_x64, libusb_files_dll_wow64, libusb_files_dll_x64
DelReg = libusb_del_reg_hw
AddReg = libusb_add_reg_hw
DelReg = libusb_del_reg_hw
AddReg = libusb_add_reg_hw
DelReg = libusb_del_reg_hw
AddReg = libusb_add_reg_hw
AddService = libusb0, 0x00000002, libusb_add_service
AddService = libusb0, 0x00000002, libusb_add_service
; Older versions of this .inf file installed filter drivers. They are not
; needed any more and must be removed
; Device properties
HKR,,SurpriseRemovalOK, 0x00010001, 1
; Services
DisplayName    = "LibUsb-Win32 - Kernel Driver 08/27/2006,"
ServiceType    = 1
StartType      = 3
ErrorControl   = 0
ServiceBinary  = %12%\libusb0.sys
; Devices
"FW Bell 5180 Gauss Meter"=LIBUSB_DEV, USB\VID_16a2&PID_5100
"FW Bell 5180 Gauss Meter"=LIBUSB_DEV, USB\VID_16a2&PID_5100
"FW Bell 5180 Gauss Meter"=LIBUSB_DEV, USB\VID_16a2&PID_5100

; Strings
manufacturer = "FW Bell"
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Message 8 of 11
The class = LibUsbDevices does not look correct for USBTMC. From what I can tell, LibUSB is a Linux driver for USB devices. It's also been ported over to windows. I would be inclined to check with the vendor and confirm that this is the correct driver.
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Message 9 of 11



I came across this thread as I'm trying to solve what sounds like a similar, if not the same, problem. I have a FW Bell 5180 Gauss Meter that I'd like to try communicating with via USB - I have installed the software that came with it (which took a while to do properly) which is happy talking to the Gauss Meter and reading back from it, however, the device doesn't appear in MAX under Devices and Interfaces. I've spent quite a while trying to work this out but am now a bit stumped.


Was the original problem every resolved? As it might solve mine too.





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