Random Connection With Single-Channel Systems - Siemens SIMATIC S7-400H Manual

7.5.4

Random Connection with Single-channel Systems

Connection via a PC as gateway
When fault-tolerant systems are connected 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 connected 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 ".
Redundancy
block diagram
Figure 7-11
S7-400H Programmable Controller Fault-Tolerant Systems
A5E00068197-04
Fault-tolerant system A
CP
CPU
a1 a1
OLM
OLM
Fault-tolerant system A
OLM/
CPUa1 CPa1
Bus1
CP 1
OLM/
CPUa2 CPa2
Bus2
Example of Interconnection of a Fault-Tolerant System and a Single-Channel
Non-Siemens System
PC as gateway Single-channel system
CP 1 CP 2 CPU
Single-channel connection
System bus as opti-
cal two-fiber ring
PC as gateway
Gateway CP 2 Cable
Communications
CP
Single-channel system
CP CPU
7-17