Active Serial Port:

The javax.comm package provides basic low-level access between Java programs and external input-output devices, in particular, serial devices. Such communications are handled using event listener technology similar to that used in the AWT package. Using the JCSP implementation of active AWT components as a model, we have constructed an active serial port (ASP), using javax.comm, that gives a channel interface that is more easily incorporated into a distributed JCSP.net collection of processes. The ASP has been tested in a real-time embedded system used to collect data from infrared detectors used to monitor the movement of pedestrians. The collected data is transferred across an Ethernet from the serial port process to the data manipulation processes. The performance of the JCSP.net based system has been compared with that supplied by the manufacturer of the detector and we conclude by showing how a complete monitoring system could be constructed in a scalable manner.