Replacement Of Bus Components In Runtime - Siemens Simatic PCS 7 Function Manual

6.1.2

Replacement of bus components in runtime

Introduction
The information in this section relates to the following bus components
● Bus cable
● Bus links
● Switches, bridges
Failure and replacement of bus components
Components of a bus system (plant bus, terminal bus, fieldbus) can be replaced when there
is no risk of accidentally affecting other components as a result of the replacement.
Before making a replacement, the following aspects must be taken into consideration:
● Bus topology (for example ring structure, spur lines, redundancy connections, disrupted
bus cable)
● Connection of the bus system to "master systems":
– The assignment of clients to servers
– The connection to time master systems
– The connection to domain controllers
– For PCS 7 OS: The setting of preferred servers
● Other disrupted components
Recommended procedure
If a bus component is partially functional, we recommend the following procedure:
● If repairs are necessary, first replace the defective bus cable.
● Insert a new bus component into the existing system before you remove the old bus
component completely.
● Avoid the occurrence of double faults.
● Replace the connection to the connected components in series (not at the same time).
High Availability Process Control Systems (V9.0)
Function Manual, 05/2017, A5E39221836-AA
Replacing components and plant changes
6.1 Failure and replacement of components
191