Information from the sensors is sent to the microprocessor. The ADC (analogue to digital converter) converts the analogue data into digital form. The microprocessor compares this digital data with stored data that meet the requirements for maintaining certain conditions. If the conditions need to be amended, the microprocessor will send out a signal to an actuator utilising a DAC (digital to analogue converter) so that action can be taken (ie. switching on the heater). This forms a feedback loop where the data from the sensors is continuously monitored.