Connected sensor system Netwerkeinheit and sensor unit

The present invention provides an associated sensor system which can be easily used by a user and capable of providing an external input each sensor unit without requiring a complicated wiring is necessary, and also provides a network unit and a sensor unit ready for use for the connected sensor system , A ring communication-memory unit of a network unit is designed with an external input request area and an external input signal is stored in a corresponding memory unit in a main control device. By performing a periodic communication between the network unit and the main control device, the external input signal is stored in the memory unit of the communication ring network unit. Thus, the external input signal to each sensor unit, which is connected to the network unit is transmitted, and each sensor unit performs the external input function.