Serial Port Monitor - The tool to test, log and analyze serial port data - RS232 sniffer software.
YAT - Yet Another Terminal - Engineering, testing and debugging of serial communication.
Listen32 - Listen32 tap into RS-232 transmit signals for monitoring bi-directional communications between two...
RealTerm - RealTerm is a terminal program specially designed for capturing, controlling and debugging binary...
Bill Serial Port Monitor - Free Software to monitor (bi-directional) Serial Port communication RS232 between two devices, use...
HTerm - HTerm is a terminal emulator for serial communication.