Error: Property Node (arg 8) in VISA Configure Serial Port

[ncm]

I am trying to control 8 USB to R232 through a Tripp-Lite 10-Port HUB (Model U222-010-R) and not having consistant results.  Right after restarting my computer I have no issues running the following program: (I tried to upload the VI directly but no success so here is the snippet)

 

I have made sure that the COM ports that I select are the one's available on both the Device manager and in NI-MAX.  But after awhile this does not work or if the HUB gets unplugged and replugged in (even if the names are correct and refreshed in both the Device Manager and NI-MAX) I get the error code "Property Node (arg 😎 in VISA Configure Serial Port (Instr).vi"  I want to be able to see these ports more consistantly without having to reboot my computer all the time.  Is there a better setup for this? The previous setup of the computer had a PCI card for this and we had no issues with the code but are running into problems with our upgrade.  The previous computer ran Windows XP and had PCI cards and the new computer I am trying to use has Windows 8 and the USB HUB.  Thanks for any help you can give!!

[mikeporter]

Unfortunately, USB hubs are known for causing all kinds of mischief when unplugged. Do you get the error from all the ports or just certain ones?

Mike...

[nyc_(is_out_of_here)]

Also, check that Windows is not turning off the USB port to save power.

[mikeporter]

RATS! I should have thought of that! I just had to fight through that very problem with a USB wifi interface...  Getting Old: It's not for the faint of heart...

Mike...

[JÞB]

Don't worry about the Windows power options ...Yet (Worry about them later)

You have a bigger problem.

If you are on bus power you have 500mA split between  8 devices. 62.5 mA is not going to work for most USB-Serial adaptors.  The chipsets themselves will draw 15mA each and drive the rs232 with 75mA.  Lord knows what the device on the other end is and if its drawing from the bus too.

Before you say "I'll just plug in the wall wart" look again! that 2.5A split up to 10 ways.

Get a device that CAN meet the 500mA per port supply demands expected for USB

[ncm]

Mike,

It depends on what I disconnect.  If I disconnect the hub it will be all the connected USB's, if I disconnect just 1 USB it will be the one that I disconnected.  Is there an alternative to a USB hub that is more friendly, or any other options?  I checked the power save and this is not the issue.

Thanks,

-ncm

[ncm]

Jeff,

Let me take a look, I will get back to you soon after I see what I have... 🙂

-ncm

[ncm]

Jeff,

This is one off the lines from Tripp-lite's specifications:

-On bus-power, 500mA from the USB 2.0 computer port is shared between the hub ports

Would this qualify to support what I need or not necessarily? 

-ncm

[ncm]

Or should I have at least a 5A hub? 

[JÞB · Accepted solution]

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@ncm wrote:

Jeff,

This is one off the lines from Tripp-lite's specifications:

-On bus-power, 500mA from the USB 2.0 computer port is shared between the hub ports

Would this qualify to support what I need or not necessarily? 

-ncm

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No! thats 50mA per port not 500mA.  a full order of magnitude under powered for USB (If you want it reliable- If you want real trouble that, shows up irratically just whenever and is a headache to track down that would do it)

Spoiler

Sarcasm.  Just one of the many services I offer.

You need 5 Amps to reliably power a 10 port hub.  The wall wart that came with your hub is rated to 2.5Amps.  Wasted money.