A SIMATIC S7-400/S7-400H is connected to two parallel Industrial Ethernet networks via the two RJ45 connections of the CP 443-1 RNA. The CP uses the parallel redundancy protocol in accordance with the IEC 62439-3 standard. It doubles the message frame and feeds it into the two connected networks. The access point on the receiver side forwards the first arriving message frame to the addressee. The frame arriving later is discarded.

Two separate interfaces:

• RNA interface with two RJ45 ports with 100 Mbit/s full duplex with autonegotiation and autocrossover functionality (no switching functionality) for connection to a PRP network
• Ethernet interface with an RJ45 port with 10/100 Mbit/s full/half duplex with autonegotiation and autocrossover functionality

There is only ever one interface active, no IP routing between the interfaces;
communication per interface only possible to the CPU in each case.

The PRP functionality can be deactivated, and the independent Ethernet interface can be activated as an alternative to the RNA interface. Standard Industrial Ethernet communication is thus also possible with the CP. Only the communication service is supported via the ISO transport protocol on the Ethernet interface, and all other services are deactivated. The CP is thus also suitable for applications that require qualification and can manage with the restricted functionality. The qualification costs can be reduced in this way.

Communication services on the RNA interface (interface X2):

• Open communication (ISO, ISO on TCP, TCP/IP and UDP):
  Multicast with UDP
• PG/OP communication: across networks by means of S7 routing
• S7 communication (ISO, ISO on TCP, client, server)
• S7 H communication for S7-400 H systems beyond network boundaries (ISO-on-TCP, ISO)
• Time synchronization by means of the SIMATIC procedure and NTP
• IP address assignment via a simple PC tool
• Security mechanisms: Access protection by means of configurable IP access list

Communication services on the Ethernet interface (interface X1):

• Open communication (ISO only)
• PG/OP communication: across networks by means of S7 routing (ISO)
• S7 communication (ISO client only, server)

Diagnostics and network management:

• Extensive diagnostics functions of all modules in the rack via Web diagnostics, integrated into STEP 7
• Integration into network management systems through the support of SNMP V1;
  the following MIBs are supported: MIBII, Automation MIB and PRP-MIB (IEC-62439-3)

Configuring of all functions with STEP 7 from V5.5 SP2 plus HSP

Module replacement possible without PG.