Siemens SIMATIC S7-400H - Random Connection with Single-Channel Systems; Connection Via a PC as Gateway

Communication Functions
8-20
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
8.5.4 Random Connection with Single-channel Systems
Connection via a PC as gateway
When fault-tolerant systems are linked to single-channel systems, they can
alternatively be connected via a gateway (no connection redundancy). The
gateway is connected via one or two CPs to the system bus, depending on
availability requirements. Fault-tolerant connections can be configured between the
gateway and the fault-tolerant systems. The gateway makes it possible to link any
kind of single-channel system – for example, TCP/IP with a specific manufacturer’s
protocol).
A software instance written by the user in the gateway implements the
single-channel transition to the fault-tolerant systems. Any single-channel system
can be linked in this way to a fault-tolerant system.
Configuring connections
Fault-tolerant connections are not required between the gateway CP and the
single-channel system.
The gateway CP is located on a PC system that has fault-tolerant connections to
the fault-tolerant system.
In order to be able to use fault-tolerant S7 connections between fault-tolerant
system A and the gateway, the S7-REDCONNECT” software package is required
on the gateway. Data conversion for routing via the single-channel connection has
to be implemented in the user program.
You will find further information on this point in the catalog called “Industrial
Communications IK10”.
CPUa2
CPUa1
CPa1
CPa2
Gateway
Redundancy
block diagram
Fault-tolerant
system a
CPU
Single-channel system
CP
CP 1 CPUCP 2
Single-channel system
CPU
a1
CP
a1
OLM
OLM
System bus as opti-
cal two-fiber ring
CP 1
CP 2
Fault-tolerant system a
Single-channel con-
nection
PC as gateway
OLM/
Bus1
OLM/
Bus2
Cable CP
PC as gateway
Figure 8-13 Example of interconnection of a fault-tolerant system and a single-channel
third-party system