I’ve started using Labview 2014 and Linx with my Arduino Uno R3 and had success with the initial startup and first example blink. It appeared to work properly and then I was starting to move on to another project. well when I tried to reconnect to the Uno pcb I’m unable to communicate anymore. and I’m only able to use the ICSP port on the uno board with a AVRISP mkII device to load a sketch. The usb port still reports the correct device port and driver info under windows 7 device manager. I thought I had a bad uno board so I got another one and the identical issue happened to the new uno R3 board. Anyone come across this issue?
It is possible you have overridden your bootloader with the AVRISP mkII. Did you attempt to run a sketch from the Arduino IDE in either case?
Also are you able to see data over the USB serial port? If you are able to access the Serial Port, that means that you have blasted the bootloader, and will need to restore it through the Arduino IDE or Atmel Studio. Just remember to get the chip fuses right (or you could lock yourself out).
Also if you have been using the mkII you could have blasted the wrong fuses in even if you put the bootloader in place. That could change the behavior of the chip in such a way that it will no longer respond to program attempts over the serial port.