RS232M Com Monitor is an excellent software tool for monitoring, troubleshooting, and logging RS232 communication. A laptop PC, USB/RS232 hub and RS232M give you a powerful, portable and sturdy tool to aid in designing and logging RS232, full duplex, data between peripherals and hosts. Of course you don't have to use a laptop, RS232M can be used on any PC with Microsoft Windows, also, data can be collected from another program using RS232 on the same PC.
You don't have to use a USB/RS232 hub either, mother board and expansion com ports can be used also. With RS232M, data can be saved to disk with time stamp information and any name you choose. Data can be logged in Hex or ASCII format, Hex is preferable since all binary values can't be represented in ASCII. RS232 data is logged in time stamp intervals from 50ms to 5s.