Nowadays, because of the current conditions in our country and globally, in general buildings security and all installations is primary concern for all of us. Primary goal is also energy save, to which there has been given a lot of importance by industry, and not only, as a result of the financial crisis, but also for the protection of the environment. Energy save is an important part of research and implementation sector, which includes methods, specialized systems, informations systems, autonomous control systems, by which the consumed energy can be reduced. In this paper, the design and implementation of united alarm systems will be presented along with a light control system. The main idea is for these two systems to be united and installed in an imaginary company whose goal is energy save with least possible interventions. In this part there will be given more emphasis given on the simulation of the PLC program for educational reasons and better presentation of its function. Subsequently, the model’s implementation process will be analyzed along with her results, which is going to give us the trigger to discuss the advantages and the disadvantages of the system. As a conclusion, possible future optimizations will be proposed as well as the possibility of the implementation in already installed systems. Aim of this thesis is to show the advantages of the systems interconnection, same time with systems ease of use as there is not any other similar system in the market

Energy saving Energy saving in lighting systems Security systems Alarm system PLC