LX Series Unit Ventilator Controller User's Guide
63
The alarm types are:
•
heartbeat alarms
•
disconnect alarms
•
status alarms
•
user-set alarms
Heartbeat Alarms
Heartbeat time values are set on the Network Input screens of the Unit Ventilator
Controller configuration wizard or by modifying SCPTmaxRcvTime.
The column heading Bit # refers to the Bit Number of nvoUValarm. The column
programmatic name refers to the programmatic name of nvoUValarm with the
format type UNVT_uv_alarms that relays the status of the object. If a heartbeat
alarm comes ON, a communication failure alarm sounds. The Bit #13 of
nvoStatus, programmatic name comm_failure, turns ON. Table 11 describes
Heartbeat Alarms.
Su
p
p
ly Temp
C°
Features of an Alarm Using High and Low Limits
Setpoint
22
20
15
25
Monitored variable falls below lower limit.
An alarm message is not sent as the monitored
variable is in the alarm state for less time than the
value of the alarm delay.
Monitored variable
enters alarm state
at this time.
10.0 min
Alarm message is sent at
this time after the expiration
of the alarm delay.
Time
18
Monitored
Variable
Lower Alarm Limit = 18°C
Upper Alarm Limit = 24°C
Alarm Delay = 10 minutes
10.0 min
Upper
Alarm
Limit
Lower
Alarm
Limit
Figure 28: Discharge Temperature Alarm