VISA Hex: 0xBFFF001D (Control pipe) error in visa test panel

[anjalihari]

Hi,
I have been trying to communicate to Tenma 72-13330 power supply via USB. The USB is actually connected to NI PXIe and PXIe is connected to the PC. I can successfully communicate with the power supply only if it is connected directly from the PC. I am trying this for the first time and really don't understand what's the issue.

I have attached the screenshots of the NI VISA Test panel. Here, it is showing as two USB interfaces, wherein for interface 0, it shows no control pipe present. And it is not possible to read or write anything. In case of interface 1, it shows Pipe in as 81 and pipe out as 02. Also, when I try to read 'IDN?' from interface 1, instead of showing TENMA power supply it shows only "T".

I have downloaded a TENMA driver file from its website(https://www.farnell.com/software/2786841.zip), but I haven’t transferred it to PXIe. Should something like that have to be done?
Does anyone know what the issue is and how to solve it?
Thank you very much in advance!
Best regards,
Anjali

[JÞB]

Strangly I believe that the TENMA Driver requires that the COM Port enumeration (the actual HKEY SERENUM VALUE) has to be COM0 -COM7.  Don't ask me why.  But the TENMA documents mention that and it is probably the only difference between using the PC and the PXIe Chassis USB Hub. 

[rolfk]

That device is obviously installed as an USB Raw device. That is not going to work like a normal serial port device like that. If you have Windows running on the PXI you definitely should install that driver. The device should be reported as Serial Port device, not as USB device and you should use an ASRL resource name to access it, not an USB::...::RAW.

[anjalihari]

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@rolfk wrote:

That device is obviously installed as an USB Raw device. That is not going to work like a normal serial port device like that. If you have Windows running on the PXI you definitely should install that driver. The device should be reported as Serial Port device, not as USB device and you should use an ASRL resource name to access it, not an USB::...::RAW.

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Hi Rolf,
Thanks for the reply. I am having Pharlap OS in my PXI. So is it possible to report it as serial port device in it. I am new to all this and any help would be appreciated.

Thanks and regards,
Anjali

[rolfk]

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@anjalihari wrote:

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@rolfk wrote:

That device is obviously installed as an USB Raw device. That is not going to work like a normal serial port device like that. If you have Windows running on the PXI you definitely should install that driver. The device should be reported as Serial Port device, not as USB device and you should use an ASRL resource name to access it, not an USB::...::RAW.

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Hi Rolf,
Thanks for the reply. I am having Pharlap OS in my PXI. So is it possible to report it as serial port device in it. I am new to all this and any help would be appreciated.

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Indeed, with Pharlap OS it is not going to be possible to install a Windows device driver. And the chance that the manufacturer has a Pharlap ETS compatible driver is extremely unlikely. They seem to use a NuvotonCDC controller from Shenzen Korad Technologies. Since it is a USB CDC device, you would have to implement the according USB protocol on the USB Raw session.

Not impossible but a fairly painful thing to do. USB Raw is definitely not trivial to handle. USB CDC is a so called composite device class that is not just used to implement virtual RS-232 ports but in fact also network interfaces and other communication interfaces. So it is fairly complex and that is probably the main reason that manufacturers like FTDI, Microchip and Atmel used their own proprietary USB class implementation for virtual COM ports, to keep it all simple.

Unless you have experience with low level embedded device communication and have already implemented some USB interface on an embedded device, it will be extremely hard to go down this route to develop a VISA USB RAW device driver for your device.