SENA Device Server and Serial_IP Application Guide - Manual (Page 12)

2.2. VirtualCOM Operation Mode
Virtual COM Mode of Sena device servers use a driver to create a "Virtual COM Port" so that
the software thinks it's talking to a serial port, but it's really talking to a LAN. When working
with Serial/IP COM port redirector, Sena device servers transmit all serial signals including DTR,
DSR and DCD.
2.2.1 Supported Models
HelloDevice PS110/410/810, Super Series, and STS Series
2.2.2 Setting in the Sena Device Server
- Set the Telnet protocol option enabled.
- The features provided by the COM Port Control protocol support are specified by
IETF RFC 2217.