Hampshire Controls Corp.
Revision 1.2
Temperature Transmitter Operating Instruction
Page 14 of 21
©2014
Door Switch Alarm (Optional)
A dry-contact switch input is available as an option on the Temperature Transmitter. Normally
this input is used in conjunction with a magnetic reed switch mounted to a refrigerator or freezer
door. If the door is left open for an unusually long period of time, an alarm condition is
generated. The switch input can be used with either normally open (NO) or normally closed
(NC) contacts. The door switch alarm uses the same delay time as the low/high temperature
alarms. The door switch alarm is indicated by a double beep from the buzzer and 5 slow red
flashes
…
…
…
…
of the LED repeated every 15 seconds.
NOTE: Depending on the configuration of the T°Sentry ALERT System software, alert messages
may be sent before, after, or at the same time (within 3 minutes) as the Temperature Transmitter
local alarm.
Battery Low Condition
The Temperature Transmitter constantly monitors the state of the batteries. When a low battery
level is detected a “battery low” notification is added to the Wi-Fi transmissions. The T°Sentry
ALERT System will then send “battery low” warning messages to those on the Temperature
Transmitter contact list. The battery low condition is also indicated locally by a single beep from
the buzzer and 5 red flashes on the STATUS LED repeated every 15 minutes.
Communication Fault
As with any wireless communication system, disruptions can sometimes occur. The
Temperature Transmitter can detect some disruptions and try to reestablish the connection to the
network. However, if the interference or outage prevents the Temperature Transmitter from
reconnecting to the network, the T°Sentry ALERT System will send “communication failure”
alerts to those on the Temperature Transmitter contact list if no data has been received from the
Temperature Transmitter for 20 minutes or more.
There is no defined local alarm for this condition. However, during reconnect attempts, the LED
quickly flash green
, and then slowly flash green 3 times
…
…
or blink red
once every 5 seconds to indicate connection or failure to connect. If you witness this, there may
be a network connection problem.
Certain communication faults may cause the unit to reset. If this occurs, the Temperature
Transmitter will go through the full power-up sequence discussed on page 7.
NOTE: If communication faults occur too frequently under normal operating conditions,
installation of additional Wireless Access Points (WAP) may be required. The WAPs should be
strategically placed to minimize the overall distance between each Temperature Transmitter and
its nearest WAP. Additionally, a wireless site survey should be conducted periodically to
determine the optimal settings for the wireless network, and to decrease the likelihood of
interference due to nearby networks.
