The square plug (type B connector) should plug into the monitor, not the PC. This is standard for pretty much all USB peripherals and as stated this is to prevent damage that could be caused by connecting 2 powered USB sockets together. A to A cables are available for some specialised purposes but they should NOT be used to connect a powered hub to a computer or to connect 2 computers together as this can cause damage. A to B is a standard USB cable and this is what you should use to connect your monitor.