Application

Sequence of Operation
Damper Position on Return from Power Failure
23
Siemens Industry, Inc.
Application Note, App 6751
140-1331
2015-07-07
ALARM ENA Values.
ALARM ENA
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.
Network Annunciation
If the LCM is connected to a field panel, alarms can be reported using the workstation
software, or by using a printer that is set up in a building manager’s office to receive
alarms. Points in the controller must be entered in the field panel’s point database
(referred to as unbundling) and defined as alarmable. For example, if the room
pressurization alarm (VOL DIF ALM) is unbundled in a field panel and a pressurization
alarm is triggered, an alarm will be annunciated across the network.
Damper Position on Return from Power Failure
On a return from power failure, the damper-command DOs (DOs 1 through 4) remain
OFF for 5 seconds prior to resuming control. Because of this it is recommended that
the Supply Damper (SUP DMPR DIR) be set for Normally Closed (NCLOSE, closed
when the actuator is retracted) for rooms where negative or neutral pressurization is
required and Normally Opened (NOPEN, open when the actuator is retracted) for
positively pressurized rooms. Likewise, it is recommended that the General Exhaust