Application

Sequence of Operation
Alarms
35
Siemens Industry, Inc.
Application Note, App 2926
140-1308
2015-07-07
Local Annunciation
ALARM ENA is an analog point whose value determines whether or not a particular
alarm activates ALARM DO7.
For ALARM ENA, the terms enabled and not enabled do not mean that a particular
alarm is enabled or not. It means whether or not a particular alarm will or will not
activate ALARM DO7. For example, if ALARM ENA is set to
1 (Vent Alarm Enabled)
and a ventilation alarm occurs, then both VENT ALM and ALARM DO7 will turn on.
However, if ALARM ENA is not Vent Alarm Enabled and a ventilation alarm occurs,
VENT ALM will turn on, but ALARM DO7 will not.
ALARM ENA Values.
ALARM ENA
0
default
No alarms are enabled.
1
Vent Alarm is enabled.
2
Alarm Switch is enabled.
4
Dif Alarm is enabled.
5
Vent Alarm and Dif Alarm are enabled.
6
Alarm Switch and Dif Alarm are
enabled.
7
Vent Alarm, Alarm Switch, and Dif
Alarm are all enabled.
NOTE:
If ALARM ENA is set greater than 7, it will default to 0.
ALM ENA is additive. For example, if ALM ENA equals 5, then either a ventilation or a
pressurization alarm will activate ALARM DO7, but the alarm switch will not.
ALARM DO7 is used to operate a local alarm annunciation device such as a light or
horn in or near the room. Inputs can be set up to annunciate alarms from any
combination of the following sources:
 Pressurization alarm point, VOL DIF ALM
(To connect VOL DIF ALM to DO 7, set ALM ENA to a value that enables the
pressure alarm (4, 5, 6 or 7)).
 Ventilation alarm point, VENT ALM
(To connect VENT ALM to DO 7, set ALM ENA to a value that enables the
ventilation alarm (1, 3, 5 or 7)).
 DI connected to a switch in the room, ALM SWIT DI6
(To connect ALM SWIT DI6 to DO 7, set ALM ENA to a value that enables the
Alarm Switch (2, 3, 6 or 7)).
 Network alarm point, NET ALM CMD
(NET ALM CMD is always enabled for local annunciation.)
ALARM DO7 turns ON if any of the enabled alarm sources indicate an alarm. ALARM
DO7 cannot be overridden.
NET ALM CMD can be commanded with the workstation software or PPCL to send an
alarm state from the field panel. This makes it possible to program unique alarm
criteria and annunciate alarms in specific rooms.