... , Plug and play compliant, hot swappable 2, Add 1 to 4 serial ports USB HUB to 4 ports RS485/422 converterA quick and ... . Features 1, Plug and play compliant, hot swappable 2, Add 1 to 4 serial ports 3, Multi-interface RS-485/422 model ... 4, USB 2.0, USB 1.0 and 1.1 compliant5, USB port ...