29/05/2023
This example shows how KNX/Logic can implement Logic conditions with If/Then/Else actions more easily than using other KNX logic products.
This requirement is for a public toilet in a large public building eg Railway or Airport. A KNX Human Presence Counter is installed (eg https://www.steinel.de/en/sensors-professional/products/products/sensors/presence-detectors/hpd2-033200.html ), to count the number of people in the male and female toilets. The logic required is as in the flowchart below. Basically, the Fan speed is determined by the number of people detected. if the number is >5, the fan speed goes from low to medium, and if >10 the speed goes to High immediately. However if the people counted is less than 9, the fan speed goes from High to Medium after some time eg 15 minutes and if the people detected is less than 5, the fan speed goes from medium to low after eg 15 minutes. The purpose is for energy saving for a facility that is open 24 hours a day 7 days a week. This system is implemented in all the toilets in the facility, thus can result in significant energy saving in the building or buildings.
Another requirement not mentioned above is that the maximum counter of the Male and Female Toilets is used in the logic, so the logic uses the larger number based on the 2 toilets in its determination of fan speed
In Comfigurator, go Modules Tab > Controller, and the right pane with KNX/Logic Properties. Select KNX > Comfort Tab as shown below.
Add the 3 KNX objects; 1 byte Scaling Values (EIS6).
0/0/2 is the Fan speed. Map to Counter 17
0/0/15 is the 1st Toilet People Count. Map to Counter 15
0/0/16 is the 2nd Toilet People count. Map to Counter 16
Each KNX object is mapped to a Counter Register in this program. Counters are 16 bit registers in Comfort which hold values and can execute Responses, or Programs based on the counter value.
See http://www.comfortforums.com/forum12/5431.html for more details
