3. Timer Design Examples 3.12 Automatic Urinal Flushing Control Program Control Purpose: z If a user stands in front of the urinal for more than 3 sec, the flushing control device will flush the urinal for 3 sec (the first flushing). When the user leaves the urinal, flush for another 4 sec then stop automatically (the second flushing). X0 Y0 3s 3s 4s Standing time The first flushing The second flushing z Stopping the first flushing and starting the second flushing if the first user leaves the urinal during the first flushing process.
The first user X0 Y0 3s The first flushing 4s Standing time The second flushing z If the second user comes before the finishing of the 4 sec flushing, the flusher will finish the 4 sec flushing process and skip the first 3 sec flushing process. When the second user leaves the urinal, the flusher will perform another 4 sec flushing. The first user The second user X0 Y0 3s 3s 4s 4s Standing time The first flushing The second flushing The second flushing Devices: DVP-PLC Application Examples 3-19 3s Device Function X0 Infrared sensor. X0 = ON when a user is detected. M0 ~ M2 Internal auxiliary relay T0 3 sec timer. Time base: 100ms T1 3 sec timer. Time base: 100ms T2 4 sec timer. Time base:
100ms Y0 Flushing valve