From HJsoft: ComTrace is a serial ports monitor product for technicians, engineers and software developers designing or debugging serial port related projects. It is a valuable tool for troubleshooting RS-232 communication between two devices. It allows you to set up a 'pass-through' connection between them using two serial ports on your PC. You can watch and log the traffic between the devices. Because ComTrace is a 100% software product, it is especially suited to inspecting host side protocol.
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