Design and implementation of 4 ports computer time service system in Taiwan

In this article, Taiwan's Computer Time Service System (TCTSS) is detailed. The system was developed by utilizing an Industrial Personal Computer (IPC) to protect the system against corrosion, moisture, dust, and to make maintenance simple. An imbedded PC bus level time code generator is synchronized to Inter-Range Instrumentation Group (IRIG) time signals, which is used to provide a source of time data and time stamps for measuring the path delay (RoundTripDelay=StopTime-StartTime). For the purpose, all formal structure and information for implementation will be specified including timing diagram, interrupt pulse generated, Software-switch, Watchdog Timer and intelligent Communication Module. TCTSS synchronizes the national standard time and distributes it in a Public Switching Telephone Network (PSTN) operating at rate from 1200 to 14400 Bit Per Second (BPS). It not only provides one way time dissemination but also offers path delay measured and compensated. In addition, the software algorithm, user interface and operation of each detailed module are discussed.