This indicates detection of the SafetyNET p RTFN CDC Safety Heartbeat command.
SafetyNET p is an Ethernet-based fieldbus communication protocol for automation use. SafetyNET p RTFN uses Ethernet/IP to communicate. It is categorized further into 2 category: CDCN and MSCN. The MSC is used for acyclic communication to transmit data on diagnostics and parameter settings. Devices write data into MSC packets and the message is transferred through a proprietary protocol, Message Transfer protocol (MSC-MTP). The CDC is used to transfer cyclic process data. In RTFN, the CDC is based on a cyclic sequence of point-to-point communications.