There is a request, spin pump with adjustable time delay so as not to overload a power failure at the start. The solution was implemented for the Simatic S7-300 in the language of STEP 7 V5. However, for easy viewing and running the simulation I transferred it to the environment LOGO! Soft.

Input I1 is the thermostat that monitors the temperature of the container. In the case of critical temperature is reached the pump switches for adding coolant. I2 represents the input switch Auto / Manual. In manual control the pump operation guarding. Time-shifting circuit monitors the delayed start, both in operations (B03) and turn off the circuit (B06). The actual switch represents samotržné relay (B02), the output state is controlled by the input signal Reset.

Circuit schema in FBD:


Circuit schema in LAD: