1.1.4 Redundancy
The Linking Device supports device redundancy. In the redundant mode, a set of two
physical Linking Devices forms one logical Linking Device. One operates as primary
device, the other as secondary device or backup device. Both devices of a redundant
set are connected to the same HSE subnet and to the same H1 links. If the primary
device fails, the secondary device automatically takes over the role of the primary device
to ensure continuous system operation. The failed physical Linking Device can be replaced
and the new device will further on act as secondary device. The system is then again
able to tolerate a failure in one of the two physical Linking Devices.
A more detailed description of the redundancy concept is given in Redundancy on
page 105.
1.2 Integration into the Industrial IT System Structure
Within an 800xA System structure as shown in Figure 1.2, a FOUNDATION™ Fieldbus
subsystem is linked to the control system via the HSE subnet. The Linking Devices serve
as gateways between the field devices on the H1 links and the HSE subnet. The
FOUNDATION™ Fieldbus subsystem consists of Linking Devices and possibly other
devices that communicate with one another using the HSE protocol and subsidiary H1
links. As a device registered as a class 42c device of the HSE profile, the LD 810HSE Ex
allows process data that are being published cyclically on the subsidiary H1 links to be
republished on the HSE subnet. By using HSE republishing, it is possible to configure
cyclical communication between field devices on different H1 links and devices on the
HSE subnet. Furthermore, alarms and events from H1 devices are communicated to the
Connectivity Servers FF, thus allowing seamless integration in the overall 800xA alarm
management philosophy.
The displayed system structure also includes redundant LD 810HSE Ex. The
corresponding H1 ports of both physical Linking Devices making up a redundant set of
Linking Devices are connected to the same H1 link. Both physical devices belonging to
a redundant set are connected via a redundant link wiring for exchanging redundancy
control information.
2PAA114135-610 21
1 Introduction
1.2 Integration into the Industrial IT System Structure
To Next Page
Loading...
Need help?
General
