We are having a lot of problems with U6 producing error code 1008 - LJE_COMM_FAILURE - Unable to send or receive the correct number of bytes.
We've upgraded to using Gold plated ferrite cored USB cables and an industrial isolated USB hub and an isolated psu but still no joy.
Is there anything we can do to make these comms more robust?
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The USB Communication Failure app note has various ideas to try and narrow down what is causing your problem:
https://labjack.com/support/app-notes/usb-communication-failure
For example, does the problem go away if you remove all your connections? If so you can then try to isolate which connection or connections cause the problem.
The system we have uses two U6 units. Along with the 1008 error messages, we are also getting 1003 and 1015.
We have also purchased a T7 to try and erradicate these errors and when we replaced one of the U6 units with the T7, the error messages stopped, it doesnt seem to make any difference which U6 we replace. It's as if using two U6 units are conflicting with each other, even though their ID's are 1 and 2 respectively.
Other strange behaviour we have noticed is that the Windows 10 PC will occasionally reset the USB connections to the U6 units, once when this happened the program running with the U6 units swapped the units over, so when it thought it was communicating with unit 1, it was actually communicating with unit 2 and vice-versa.
Error 1003 is LJE_INVALID_HANDLE. Double check that your code isn't changing the value of your U6 handle by accident. The UD driver should only change the handle value during the open call.
Error 1015 is LJE_DEVICE_NOT_CONNECTED, and could be related to error 1008 if the U6 stopped responding. When this error occurs, is the power LED on or off.
Regarding error 1008 troubleshooting, try different USB ports and see if that makes a difference. If possible, try a different computer to check if this is a general issue or just isolated to one computer. If that doesn't help, disconnect all connections to your U6s. If the errors stop with no connections, please describe what you have connected to your U6s when the errors occur.