Sutron Corporation X-Link Operations & Maintenance Manual, Rev 1.63 5/24/2016 pg. 52
5.3.4.
Listening
An X-Link can be set up to always be listening, which means that it will act as a
server, accepting TCP/IP incoming connections. Sutron's AutoPoll PC software
can periodically reach out to a listening X-Link station and collect sensor data
from X-Link. In the listening mode, X-Link will keep the modem on at all times,
resulting in higher power consumption.
The transmission status (use LinkComm's Telemetry tab or issue STATUS TX
command) indicates the IP address assigned to X-Link by the service provider.
The
Listen Port
setting determines which port X-Link remains open.
You can send X-Link a message with the TXLISTEN command that would cause it
to temporarily go into listening mode.
Listening is automatically turned on by X-Link for 10 minutes :
At boot up
When the station is connected to, whether via USB, over the modem, or
over Wi-Fi
When an SMS is received
When the wakeup button is pressed, and when the station goes into alarms,
listening is automatically turned on for one hour.
5.3.5.
SMS Transmissions
X-Link can use SMS (text messages) to deliver sensor data. It can use SMS
messages as a primary means of data reporting, or only if the primary and
backup servers cannot be reached.
The system is able to make scheduled transmissions to IP servers and may be
configured to transmit SMS messages if communications fail to the IP addresses.
Additionally multiple phone numbers may be used:
