ComSpy 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.
LicenseFree to try
File Size3.7 MB
Operating System Windows XP Windows Windows 98 Windows Me
System RequirementsWindows 98/Me/XP, two RS-232 Serial Ports