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Sutron Corporation Satlink Operations & Maintenance Manual, Rev 8.04.2 11/3/2016 pg. 110
10.5.2.1.
Cell Listening
If enabled,
Cell Listening
will cause Satlink to keep the cellular modem on all the time. This
makes it possible to connect to Satlink with LinkComm over the internet at any time. However, it
significantly increases the power consumption. When listening, Satlink will act as a TCP/IP
server, ready to accept incoming connections from LinkComm.
If Cell Listening is not enabled, Satlink will only power on the modem when it makes
transmissions and when it checks for messages.
If power consumption is of concern, setup Satlink to periodically check for messages (see Msg
Interval below). Shorter intervals result in higher power consumption. Longer intervals mean a
longer response time. For example, if Msg Interval is one hour, it may take up to one hour for
Satlink to receive a message.
Once there is a need to connect to Satlink, send a message to Satlink asking it to start listening.
That message should say
!CELL LISTENING=ON
Once Satlink receives the message, it will send a reply. From that point on, Satlink is online and
available to connect. It will stay online until listening is turned off. Use LinkComm to connect to
Satlink and perform the appropriate operations. Do not forget to turn off listening before
disconnecting.
To have Satlink only turn on listening for a limited time period, use the LISTEN command. For
example, to have Satlink go online for two hours send an SMS saying
!LISTEN 7200
Two hours is 7200 seconds.
Please note that the Msg Interval setting (described below) determines how often Satlink checks
for incoming messages. If that is set to six hours, it means that it may take up to six hours before
Satlink receives to incoming messages.
10.5.2.2.
SMS Listening Only
If SMS Listening Only is enabled, Satlink will not go online when listening. Instead of being able
to accept incoming TCP/IP connections, it will only be able to receive incoming SMS.
LinkComm will not be able to connect to Satlink remotely while this setting is active.
Please note that if Satlink is setup for internet transmissions, it will go online when transmitting
regardless of the SMS Listening Only setting.
10.5.2.3.
Cell Msg Interval
The Cell Msg Interval setting dictates how often Satlink will check for incoming SMS messages.
This setting is near identical to the
setting. Please read that section for
details on message checking.