The TCP Server mode in NPort devices can only be used for raw data transmission. Hence, this mode has limitations on detecting and controlling the serial line status and sending serial break signals. However, an IPSerial library is included with the NPort 5000 Series device that can help you with these requirements.
The IPSerial library is specifically designed to help Windows developers implement a variety of functions on serial ports. Common uses of this library include interfacing with older serial devices, such as printers, which require specific assertions on the RTS/CTS, DSR/DTR, or break signals for them to work properly. The library is included with the standard NPort Administration Suite and is installed by default in the IPSerial folder. Moxa also provides a help file (ipserial.chm) and an API along with the sample code.