Nico (Customer) asked a question.
Temperature control for a Click PLC
Good day.
I would like to control a boiler pump with a temperature sensor. So when the sensor measures 60 degrees is switches the pump on and when it reaches 64 it switches the pump off again. But then I want to have a temperature setting on my C-more HMI where we can set the temperature to different settings. For example Set it on 62 and then the pump will start up at 60 and switch off at 64. When I set it to 64 with a up/down button on the HMI. it will switch on at 62 and off at 66.
Do I need an up/down counter for the setting. and then a "compare" to keep it. for example counter is on 60, then DF1(Sensor) >= CTD1 to switch on and DF1 >=CTD1+4 to switch off pump?
Any examples please.
Thank you
Just to be sure, the pump is on only when the temperature is equal to or above the lower setting and less than the upper setting. Just create two math blocks, one which subtracts 2 from the HMI setting to store in a variable (it doesn't need to be a counter) and the other which adds 2 to the HMI setting for storage in another variable location. Then perform your comparison as you indicate. Post your program here for us to check.
Sent you the logic in a private message. Did you receive it?
You may wish to set limits in your code for high and low points of the HMI value. The display doesn't have a setting for that.
That makes sense yes. Thanks