Table of Contents
Advertisement
Features of SNS AC-powered Sensor Devices
Buzzer
AC-powered sensor devices are equipped with an alarm buzzer. When an alarm is active, the
buzzer sounds continuously, if Enable Audio Alerts is enabled (checked) on the sensor device's
Edit Sensor Device page in the AMP. Pushing the service button when the buzzer is sounding
silences the buzzer but does not acknowledge the alarm on the AMP.
Monitoring Thresholds
AC-powered sensor devices permit you to set temperature and humidity monitoring thresholds. If
the thresholds are exceeded or, depending on the configuration, exceeded for a period of time, the
sensor device enters an alarm state. To set monitoring thresholds and download them to the sensor
device, you edit sensor device information on the AMP. See the SNS Temperature and Humidity
Sensors User Guide for information on editing AC-powered sensor devices, including monitoring
thresholds.
Operational Sequences
Turn on the Sensor Device
Plugging in an AC-powered sensor turns the device on. When the device is first powered up, it will
turn on all of the LCD digits and the red LED. After 1 second, the display will briefly blank out and
the LED will be turned off. The device will then read all of its configuration data out of non-volatile
memory. If the device has never checked into an AMP, the default settings will be used. The default
settings are:
•
Check-in Interval: 1 hour
•
Temperature Display: Fahrenheit
•
Alarms: None
After the configuration data is loaded, both probes inputs are sampled and the display begins
showing the temperature. The device then turns on its radio and proceeds to communicate with the
AMP.
Normal Operation
Single probe temperature sensor devices update the probe reading every three seconds. Dual
probe temperature sensor devices alternate between showing the temperature of probe 1 and
probe 2 every three seconds, while temperature and humidity sensor devices alternate between
showing temperature and humidity every three seconds. Before the display changes to show the
other reading, both inputs are sampled. The min and max temperatures on the display are checked
every time a new temperature sample is taken. The min and max on the display are a daily min and
max and every 24 hours from power up the daily min and max will be cleared and replaced by the
first sample of the next 24 hour period.
Check-in with the AMP
The sensor device checks in with the AMP at regular intervals (default 1 hour), starting when the
device is powered up. If a check in with the AMP fails, the information is stored in non-volatile
memory. The non-volatile memory is capable of storing 2046 readings. If the number of failed
check-ins exceeds the size of the non-volatile memory, the oldest readings are overwritten. Any
data stored in non-volatile memory will be lost if the device loses both AC and backup power.
Primex Wireless, Inc.
SNS™ Temperature and Humidity Sensors Installation Guide
Monitoring Thresholds
15
Advertisement
Table of Contents
