USB Plug-n-Play Devices (Windows)

[1984]

Hi community,

In the last days I have faced Error -50808 on my cDAQ 9174 couple times. This seems to be a fatal error, I lost my connection to the chassis completely. In MAX the device seems to be offline and I can not communicate with it at all. I need to perform a power cycle on the chassis to make it work again. This is a major concern for right now as we try to perform long term measurements.

What could cause an error like this and how can I get rid of this? 

I use LabVIEW 2013 with DAQmx 9.8

thanks!

[HeroOfHyrule]

This error seems to be associated with plugging in a USB device while a DAQmx Task is running. That entire cDAQ device the task is running might get into a bad state.

You could try power cycling the device and then running the DAQmx task after the cDAQ is back up and running. 

[1984]

I certainly did not plug anything into the computer while the app was running and both the computer and the cDAQ chassis are powered via a UPS.

As I wrote power cycling resolves the issue, but thats not an option. Its either work reliably or it should not run at all.

[HeroOfHyrule]

1984,

DAQmx returns these errors after the host PC's USB controller reports a USB transaction error. 

To recover from this state, you may use this : Programmatically Reset USB DAQ device in LabVIEW

The underlying issue could come from the host controller, the device, or even the USB cable. Some host controllers are more susceptible than others to encountering these transaction errors.  It is recommended to double-check your USB cable and if necessary try the device on a different host controller.

You could try a different USB host controller (PCI USB host controllers cost typically between 20 and 30 dollars).

You'll find all these information in the following document : Why Do I Receive Error -50405 or Error -50808 Using an NI USB DAQ Device When Inserting or Removing ...

FYI, a customer who met the same issue got the 9172 working by using an externally powered USB hub.

Regards,

[JÞB]

And I'll break out the FAQ article yet again

USB Plug-n-Play Devices (Windows)

Options

‎01-22-2012 02:20 PM

In this topic we will discuss some of the common problems that have been observed using USB devices with LabVIEW on Windows operating systems.  Many of these points are also applicable to other environments but the examples will be use the Windows 7 OS.

FAQ 1 : My USB device stops working unexpectedly.

The first thing to look at is the OS power saving options.  There is a global trend towards developing "Green" electronics and energy star ratings are getting fairly common.  "If its not being used shut it off" is nothing new.  Cavemen learned how to bank a fire to preserve energy that would otherwise be wasted.  Likewise, the Windows OS has a power saving feature to shut down power to the USB hubs when no user activity is present.  In Automated systems this feature can cause problems since removing USB hub power will shut down the USB device.   Solution: Use the device manager to change the USB hub Power Options.

FAQ2: I set the power options and my device connection is still unreliable: Remember, those computer USB ports are often the cheapest that can be mounted on the chassis and share the PC system power supply to supply USB Power. Most uses of USB are temporary connections like a thumb drive or a camera.  These connections do not require high reliability since the user is right there interacting with it.  Power surges and fault tolerance at worst cause the operator to retry the data transfer.  Automated systems require a bit more robustness.  Solutions:

1) ALWAYS use an external self powered hub.  Perform your engineering due diligence and inspect the devices specifications too- If you can't find them for that device that should clue you to seek an product from a vendor that WILL publish their specs.

2) High noise environments require the use of ferrites on the USB cable- and don't buy the cheapest cable either! The cheap ones are poorly shielded.  

3) PROTECT the HUB connections-  If you have a USB2.0 device and Joe User plugs in a 1.0 device in a open slot managed by the same hub- Bingo every port on the hub may back convert to USB1.0.  WORSE there are a lot of damaged or marginally engineered USB devices out there.  Joe User's device may cause power fluctuations when it is inserted or removed from the hub just don't let it happen!

[JÞB]

In this topic we will discuss some of the common problems that have been observed using USB devices with LabVIEW on Windows operating systems.  Many of these points are also applicable to other environments but the examples will be use the Windows 7 OS.

FAQ 1 : My USB device stops working unexpectedly.

The first thing to look at is the OS power saving options.  There is a global trend towards developing "Green" electronics and energy star ratings are getting fairly common.  "If its not being used shut it off" is nothing new.  Cavemen learned how to bank a fire to preserve energy that would otherwise be wasted.  Likewise, the Windows OS has a power saving feature to shut down power to the USB hubs when no user activity is present.  In Automated systems this feature can cause problems since removing USB hub power will shut down the USB device.   Solution: Use the device manager to change the USB hub Power Options.

FAQ2: I set the power options and my device connection is still unreliable: Remember, those computer USB ports are often the cheapest that can be mounted on the chassis and share the PC system power supply to supply USB Power. Most uses of USB are temporary connections like a thumb drive or a camera.  These connections do not require high reliability since the user is right there interacting with it.  Power surges and fault tolerance at worst cause the operator to retry the data transfer.  Automated systems require a bit more robustness.  Solutions:

1) ALWAYS use an external self powered hub.  Perform your engineering due diligence and inspect the devices specifications too- If you can't find them for that device that should clue you to seek an product from a vendor that WILL publish their specs.

2) High noise environments require the use of ferrites on the USB cable- and don't buy the cheapest cable either! The cheap ones are poorly shielded.  

3) PROTECT the HUB connections-  If you have a USB2.0 device and Joe User plugs in a 1.0 device in a open slot managed by the same hub- Bingo every port on the hub may back convert to USB1.0.  WORSE there are a lot of damaged or marginally engineered USB devices out there.  Joe User's device may cause power fluctuations when it is inserted or removed from the hub just don't let it happen!