slot communication network management (Ethernet-Powerlink) (SCNM)

InEthernet Powerlink(EPL), the stochastic access method familiar from Ethernet is replaced by an isochronous time- slot method.

In this technique, a central station, the Manager Node( MN), distributes access authorization to the connected stations. In Ethernet Powerlink, this procedure is called Slot Communication Network Management (SCNM) and forms the basis for deterministic access.

In terms of concept, one station assumes the function of the manager in Ethernet-Powerlink. It sets the timing for all connected stations, the Controlled Nodes( CN). The controlled nodes are only allowed to transmit when they are requested to do so by the manager node.