Siemens SIMATIC PCS 7 Function Manual

7.13 Redundancy behavior of the PCS 7 OS, SIMATIC BATCH and
SIMATIC Route Control servers
Error-free System
A redundant server pair is considered to be fault-free when the following conditions are met:
● Both servers are in process mode (master or standby).
● All process mode data are synchronized between the servers.
Failure of a server computer (computer of a server pair)
Order of the reactions Reactions
Failure at the master server (Serv‐
er_a power off)
Failure at the standby server (Server_b
power off)
For computers with a
server function or
computers with a
combination of server
functions
● BATCH server
● OS server
● Route Control
server
Standby server (Server_b) becomes
master
No redundancy switchover master re‐
mains master
Failure of the terminal bus
Order of the reactions Reactions
Failure at the master server (Serv‐
er_a)
Failure at the standby server (Serv‐
er_b)
Only for BATCH server
or for BATCH server in
combination with Route
Control server
The dialog "Restart request" appears at the server affected by the failure.
Only for BATCH server
or for BATCH server in
combination with Route
Control server
Network adapter for terminal bus and redundant link are deactivated.
For computers with a
server function or com‐
puters with a combina‐
tion of server functions
● BATCH server
● OS server
● Route Control
server
Standby server (Server_b) be‐
comes master
No redundancy switchover master re‐
mains master
Failure, switchover and reintegration of high availability components
7.13 Redundancy behavior of the PCS 7 OS, SIMATIC BATCH and SIMATIC Route Control servers
High Availability Process Control Systems (V9.0)
Function Manual, 05/2017, A5E39221836-AA 239

Siemens SIMATIC PCS 7 Specifications

General

Brand	Siemens
Model	SIMATIC PCS 7
Category	Control Systems
Language	English