iPad wire-connection issues
It's likely that there is a fault with the connector either in the computer, or the cable, as you say you've tried another port and it's working I would suggest that there is a fault with that port.

Do other devices have similar intermittent disconnection issues?

As the USB bus on most modern computers also supports the keyboard, trackpad, FaceTime/iSight Camera and the SD Card reader it's likely that the USB device rapidly connecting and disconnecting dozens of times is causing either a software issue in the kernel extension that manages USB devices, or causing the hardware to shut down the USB hub in the machine to protect it from damage.

Either way, I would suggest trying with a couple other devices, and also check with another Lightning Cable for your iPad and if the issue persists seek service at your nearest Authorised Apple Service Provider, such as an Apple Store.