Why is the device connected to the Serial Port of my computer not communicating with Openlab?

Technical Note: 103
Reads: 6953
Creation Date: 27/04/2000
Modification Date: 19/08/2005

If a serial device has previously been communicating with Openlab but the computer crashed and now on restarting the computer communication has been lost, check the session log for messages regarding opening the relevant serial port. The message "The serial port x could not be opened for device y because the port is in use" indicates that you must restart the computer to clear the serial ports and this will correct the communication problem.

This problem occurred on late versions of Mac OS 9. It should not occur on Mac OS X.