Siemens SIMATIC PCS 7 OSx Hardware Manual

Alarm Applications/Failover Option
A-8
SIMATIC PCS 7 OSx 4.0.0 Hardware (PA RISC)
A.4 Connecting Options: Failover Circuit
If you are installing more than one supervisory station, you can connect
these stations so that one station serves as a backup. The S7–200 CPU 212
on the backup station detects the loss of a primary alive signal when the
primary station fails. The backup station then assumes the primary role. T o
provide failover capability , connect the S7–200 that is attached to the
primary to the S7–200 that is attached to the backup.
Although operator stations cannot have the backup role, you can connect
the failover circuit to them. When connected to the failover circuit, the
operator station detects the failure of the primary as quickly as possible.
This allows the operator node to resynchronize with the new primary more
quickly . Refer to the SIMA TIC PCS 7 OSx System Administration Manual
and the SIMA TIC PCS 7 OSx Process Configuration Manual for additional
information on multiple-station installations.
Use 28 A WG wire with a maximum of 16 receiver connections for the
failover ribbon cable. Each S7–200 provides 24 VDC power for the failover
circuit. T able A-3 shows the pinout for the S7–200 JP3 connector . Figure A-3
shows the wiring diagram for the failover circuit. The loopback socket is
required to route the failover signals to all OSx stations.
Table A-3 S7–200 CPU 212 JP3 Pinout
Pin Function
6 Primary Alive Output (Q0.0)
10 24 volt Present Input (I0.1)
13 Primary Alive Input (I0.0)
19 24 VDC+ (L+)
21 Input Common (1M)
24 24 VDC– (M)
Any pin numbers not listed have no connections.

Siemens SIMATIC PCS 7 OSx Specifications

General

Brand	Siemens
Model	SIMATIC PCS 7 OSx
Category	Control Systems
Language	English