When the PLC power on, the code inside the interrupt task is executed every interruption, and you can write "AA1" inside the interrupt handler. When you start to use the timer, just record the current data of A. Let's say A1; the interval is Interval CurrentDataOfA-A1. Then compare Interval to the time you want. Build Time 24 hours. 350,000 In-stock Parts Free DFM File Check Explore JLCPCB Assembly Quote Now . 3D Printing. From 1. Build Time 48 hours. Price as low as 0.07g SLA, MJF, SLM, FDM, SLS Resin, Nylon, Metal, ABS Quote Now . SMT. Professional Learning Center at Teachers College, San Joaquin (TeachCollegeSJ) supports educators growing & improving throughout the entirety of their career. Under the 24 hour clock system, a day starts at midnight, (that is, 0000), and the days last minute starts at 235959 and then ends at 240000, which is typically identical to 0000 (of the next day). Midnight is shown by 2400 and it means the end of the day. 0000 means the day has begun. For instance, one can say, Monday at 2400 ..