With this program block you can prevent too frequent switching of pumps etc by using hysteresis
First connect an analogue sensor to the input AI. If this analogue sensor value is below the value of the parameter Von then the output Q is on. Q remains on until the analogue value has risen above the value of parameter Voff.
This can prevent frequent switching on/off which can damage pumps etc. The range between Von and Voff is called hysteresis or the deadband.
In this example the pump would be turned on when the water level is less than 5 (switch on Von). The pump will then stay on until the water level has risen to a value of 8 (switch off Voff), and then the output will be turned off.
In this example, the pump would be turned on when the level is less than 5 (from). The pump then stays on until the analog value has risen to a value of 8 (V off) and then turns off again.
Heating control, flow control, climate control.