With the SY-HUB15054 USB 2.0 to 4 Port Serial Adapter, you are able to connect a single USB port to control and monitor four RS232 serial ports. This can then be used on applications such as POS Printer Terminal, Networking Systems, PLC Instrumentation device, Data Acquisition, and I/O Control modules.
USB 2.0 to 4 Port Serial RS422/485 Adapter
