With Serial Port Monitor you can:

Analyze serial port activity

Serial Port Monitor can connect to a COM port, which is even already opened by any application, and can start monitoring it right away. All the data that goes through the monitored COM port will show up in our monitoring tool. Everything is captured in real-time, so you can track down problems immediately.

Moreover, you can redirect all the monitoring data to the specified file or you can copy all recorded data to clipboard. Serial Port Monitor gives you the ability to intercept and record all serial input/output control codes (IOCTLs), tracking their full details and parameters. You can save any monitoring session and load it next time whenever you need it.
monitor & analyze COM port
　

Read captured data in different ways

You can view data in all 4 monitoring views at the same time: table, line, dump or terminal mode, each providing a different way to represent recorded serial data. Serial Port Monitor lets you choose monitoring filters, thus saving your time and letting you track down only those events you are interested in.
send data to COM port
　

Emulate data sending to serial device

You can send data in various formats (string, binary, octal, decimal, hexadecimal, mixed) to monitored serial port as if it was sent on behalf of monitored application using terminal mode feature of Serial Port Monitor. Thus you can follow the reaction of the monitored serial device to some special commands and data.