49
Tinf - 0,1°C
Tinf
1
3
2
Tinf + DTA
13.6.3 Alarm for temperature lower than the lower temperature threshold value
The GSM chronothermostat can send an SMS alarm message if the temperature is lower than the
threshold set by the user; this alarm condition is detected when the measured temperature is less than
the set lower threshold value (indicated by
Tinf
) by at least 0�1°C�
After sending the alarm SMS message to the telephone numbers previously set, the chronothermostat
remains in the state of “alarm sent” and, as long as it remains in this state, it will not send any more
lower temperature alarm messages; this condition persists until the measured temperature rises above
the value of:
Tinf + DTA
where
DTA
is the temperature differential defined for managing the temperature alarms and its value
is the same for managing both the lower and higher temperature alarm�
The following figure outlines what has just been described:
1: Detection of measured temperature alarm less than Tinf
2: Send SMS alarm message (status: lower temperature alarm)
3: Reset alarm; the device can now detect a new lower temperature alarm.
For managing the lower temperature alarm, it is necessary to carry out the following configuration
procedures:
• Setting the value of the lower temperature threshold�
• Enabling the alarm�
• Associating the alarm with the telephone numbers to which the SMS message must be sent�
• Changing the value of the temperature differential DTA (optional)�
• Customizing the Address Msg� (optional)�
The curve represents
the
Measured
Temperature
