USBTMC and USB RAW device detection

[MarcelJanssen]

Hi,

I'm creating a USB device and would like to use it in Labview. I know how to deal with RAW devices and this all works fine with my device but I'd like to try to make the device USBTMC compliant.

I have changed the descriptors and implemented the USBTMC spec into my firmware but when trying to connect it I get the following :

1) Windows recognises the device as "USB Test & Measurement device", which does sound fine to me although I would like it to show a more recognisable name like "USB oscilloscope". Actually, I think it should just show the iProduct string from my Device descriptor.

I guess this can be done but can't find anything about this. Is there any documentation on this ?

2) In this mode the used driver is NIUSBTMC.sys. This seems correct, but somehow my device doesn't show up in NI-MAX.
When using NI-spy I do see some communication which fails :
> 367.  viFindRsrc (0x0334AE28, "/USB?*", 0x00000000, 0, "")
> Status: 0xBFFF0011 (VI_ERROR_RSRC_NFOUND)

Probably there's a problem with my firmware regarding NIUSBTMC.sys. Is there any documentation on NIUSBTMC.sys ?

Regards,
Marcel

[Albert.Geven]

Hi marcel

keep me informed,
are you working late?

[MarcelJanssen]

Hello Albert,

Working late indeed 🙂

Anyway, I think I found the root cause but will first make sure before posting any result.

Regards,
Marcel

[MarcelJanssen]

Hello Albert,

It turned out I had a mistake in my device descriptor. iSerialNumber may not be zero according to the USBTMC spec.
The device shows up in NI-MAX just fine now.

Time for some golden liquid with foam now 🙂

regards,
Marcel

[Albert.Geven]

good work