Firewall-rated comms for the pit floor
The Siemens 6GK7543-1AX00-0XE0 CP 1543-1 is a compact S7-1500 single-width communications processor that brings a stateful inspection firewall directly onto the PROFINET interface — no external security appliance needed between the PLC and the plant network. Rated for 10 to 1000 Mbit/s on the first interface, it handles the bandwidth for both process data and IT traffic without bottlenecking the backplane.
Routing and security posture
Static IP routing is supported; dynamic routing protocols (RIPv1, RIPv2, OSPFv2, and their IPv6 equivalents) are not. The module also supports SNMP v1 and v3, LLDP, DCP, NTP, and IEEE 802.1x authentication — a full set of industrial network services for a managed PROFINET cell. The firewall runs stateful inspection, meaning it tracks connection state and blocks unsolicited traffic at the IP level, which is a step above simple packet filtering.