Application 2: Dual Alarms; General Description - Siemens SIMATIC PCS 7 OSx Hardware Manual

A.3

Application 2: Dual Alarms

General
Description
A-6 Alarm Applications/Failover Option
Figure A-2 shows a typical dual-alarm application using two alarm
annunciators. This configuration provides both warning and critical alarm
levels. Use this application in a multiple-station configuration to provide
separate warning and critical alarms from each OSx station. Since there is
no manual silence circuit for these alarms, you must silence the alarm from
the operator keyboard or screen.
Use the Output Channel #1 for the warning alarm annunciator switch and
Output Channel #2 for the critical alarm annunciator. The numbers for each
of the outputs are the pin numbers of the external connector.
You need two external power supplies (a 24 VAC or 24 VDC and a 120 VAC)
for this application. Use a 120 VAC power supply to drive both alarm
annunciators and a 24 VAC or 24 VDC power supply for both alarm latching
circuits.
To run this application, you need to make the following configuration
changes in the Event Preferences Configuration dialog box. Set the External
Alarm Annunciator field to
. For instructions on configuring the alarm output mode, refer to
Continuous
the section called Event Preferences Configuration in the chapter on
configuring OSx stations in the
Administration Manual.
This configuration change allows the output contact to latch on when the
system is in alarm. The output contact does not unlatch until you clear the
alarm condition.
NOTE: If you have difficulty with your system, contact the Siemens
Energy & Automation, Inc., Technical Services Group in the U.S.A. at
423–461–2522, or outside the U.S.A. at 49–911–895–7000.
and set the alarm output mode to
Enabled
SIMATIC PCS 7 OSx System
SIMATIC PCS 7 OSx 4.0.0 Hardware (PA RISC)