For acceptance and inspection of new installations but also for long-term monitoring of PROFInet-networks, Indu-Sol has developed the PROFInet INspektor. This one monitors the telegram traffic while representing a measuring device and an intelligent measuring point. It provides information about parameters like utilization rate, data throughput and telegram gaps. Pre-defined trigger functions sum up the events, a potential-free contact raises an alarm as soon the pre-defined thresholds are exceeded. At any time the current state of the communication quality in the network concerned can be reflected and displayed on any PC with the help of an integrated web server. Thanks to the data storage device events can be tracked and evaluated later. The PROFInet-INspektor allows both a temporary and a permanent monitoring of the data traffic under current production conditions.