I would recommend you to look at Serial To Ethernet Connector. This product will hopefully be the solution you seek. Please, be informed that Serial to Ethernet Connector is an advanced software solution that allows you to share more than 255 serial port devices over network easily turning your computer into low-cost terminal server. Thus, any serial port device connected to a COM port can be accessed from anywhere in the world (via Internet or LAN) as if it is attached directly to the remote PC.
When the attached serial port device sends communication data, it is actually transmitted over TCP/IP network and back from the network to your serial device.
To read more about its features, please visit the page:
To download free trial version and test its functionality yourself, please follow the link: http://www.eltima.com/download/serial-over-ethernet/