I am having issues with a device connected to my Sun V440 ttyb serial port. How would I test the connectivity of the port to see if any data is moving across the connection? I am trying to see if the port went bad or not.
An authoritative answer would require a handy oscilloscope and a knowledge of RS-232 signaling (thankfully, a dying art).
An ad hoc approach is to set up and test a cable and terminal emulator (in DCE mode) with a known-working system then try it with your malfunctioning system. For more details, see Sun Fire V440 Server Administration Guide, "How to Access the System Console via a Terminal Server", p. 59.