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Troubles with USB-over-network and DAQmx

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Troubles with USB-over-network and DAQmx

Hello NI forums,

 

I'm trying to get a myDAQ working from a remote server rack using a USB-over-network device (a SEH INU-100). The USB port emulation server recognizes the myDAQ: it appears as a Windows-recognized USB device, and shows up properly in NI Max. Some DAQmx functionality (e.g. AO) works, but AI acquisition does not work - the device returns "the specified resource is reserved" error. The myDAQ/NI software configuration has been tested working when directly connected to the pc, and not using the USB-over-network device.

 

I believe that the DAQmx driver is having difficulty with the USB-over-ethernet device. Does anyone have experience with such a setup? Is there any helpful customization I have access to regarding the myDAQ?

 

Cheers,

Alex

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Re: Troubles with USB-over-network and DAQmx

The problem is most likely that the USB over Ethernet extender does not provide a fully transparent USB connection. In my experience there exist no extenders that provide such a connection for more complicated devices like the myDAQ or other USB data acquisition devices. The problem is that such extenders are tested with the most common commercial and consumer grade USB devices only. And the USB specification itself is such a large and enormous field that is is basically impossible for such a device to implement every possible transfer mode, endpoint, and other feature that an USB device could use. And the Chinese OEM has long ago moved on to developing a new device and has almost zero resources assigned to support existing products.

 

Customization of the myDAQ device itself is almost certainly not possible. The NI driver uses certain features of the USB spec that your extender fails to transparently support. NI could maybe change or rewrite the driver to not use that feature and make it work with your specific extender but that would almost certainly mean that a different extender will get into new problems. Unless you have a real business case to make to NI about buying at least several thousand of these devices if this works with your extender, there is very little chance that the driver would be specifically changed to work in this way. And a future update to the driver and/or your extender firmware could mean that it fails again anyhow.

 

Basically bus extenders of any kind, be it PCI, PCI express, USB or others are always a very tricky business. They may work with a certain hardware or not, and if they don't there is very little you can do to make it work anyways, even if you "own" the hardware and driver and could make changes to your driver source code to work around such an extender limitation, as debugging this is a major pita to do and only possible with very specific hardware bus debuggers.

 

The right course of action would be to contact the bus extender manufacturer and ask them about a new firmware version that might support more USB bus features and if you are very lucky that update fixes the issue the myDAQ driver is running into. More often than not however these devices are nowadays sold by companies who know very little about it except the post order address in China where they get them from. And the Chinese OEM has since moved on long ago to developing new devices and has zero resources assigned to support existing products.

Rolf Kalbermatter
Averna BV
LabVIEW ArchitectLabVIEW ChampionLabVIEW Instructor
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Accepted by topic author Bob_Schor
07-10-2018 10:28 AM

Re: Troubles with USB-over-network and DAQmx

SO! After communication with SEH technologies, they helped me out with the correct firmware/software versions required to get this working. They were quite quick about it, too - for future reference for anyone looking into their products.

 

In the case that anyone stumbles across this forum post in the future, I got the myDAQ to work remotely using the hard/software listed below.

 

I stress-tested the acquisition mode. I reached 25MS total before buffer overload with 2x channels @ 200kSPS, but results will vary depending on network. Fun fact, this adapter is allowing me to use a VM as my "rack PC."

 

Thanks for your input, Zealot, it helped guide me to a solution.

 

Cheers!

 

SEH INU-100 USB-to-ethernet adapter

Firmware version: 365.12

INU control center version: 14.5.9

SEH UTN manager version: 3.1.10

 

NI myDAQ

NI software: [attached screenshot]

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Re: Troubles with USB-over-network and DAQmx

Very good report! And I'm pleasantly surprised with the technical support of that company. Hats off!

Rolf Kalbermatter
Averna BV
LabVIEW ArchitectLabVIEW ChampionLabVIEW Instructor
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