Siemens SIMATIC PCS 7 OSx Hardware Manual

Alarm Applications/Failover Option
A-3
SIMATIC PCS 7 OSx 4.0.0 Hardware (PA RISC)
The S7–200 CPU 212 allows you to connect external sirens and warning
lights to your process. T able A-2 shows the outputs and functions for the
S7–200.
Table A-2 S7–200 CPU 212 Output Connectors
Terminal Function
1L
Watchdog common and Channel 2 normally closed contact
(used for failover)
Q0.0 Watchdog—normally open contact (used for failover)
Q0.1 Watchdog—normally closed contact
Q0.2 Channel 2—normally closed contact
2L Channel 1 common and Channel 2 normally open common
Q0.3 Channel 1—normally closed contact
Q0.4 Channel 1—normally open contact
Q0.5 Channel 2—normally open contact
NOTE: The Channel 2 normally closed contact is not necessary for most
alarm applications. Channel 2 shares a common (1L) with the watchdog
normally open contact. The S7–200 provides 24 VDC power for the failover
circuit. The 24 VDC source is connected to the watchdog common (1L). If the
Channel 2 normally closed contact is used, be sure that no conflict occurs
with the failover circuit.
Exter nal Connector

Siemens SIMATIC PCS 7 OSx Specifications

General

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