Xylem SIT65 SATELLITE INTERNET TELEMETRY - Manual (Page 14)

Global Water Instrumentation
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converting water level to flow, or can be used as best-fit polynomial approximations
for almost any non-linear sensor or function. These features are available in both
databases, but they work differently and the format won’t be detailed here.
Alarms
Alarm notifications can be sent via email or text messaging when incoming data
exceeds thresholds defined in the alarms section of the databases. Both high and
low threshold settings are available for all analog inputs to alert the user based on
water level, wind speed or any other analog parameter. Digital inputs can generate
alarm messages based on the state of these inputs, a door being opened or a power
failure for example.
Besides transmitting data at regular intervals, the SIT65 can be programmed to
transmit upon any change of state on any of the digital status or accumulator inputs.
These alarm transmissions occur with all changes of state. A door switch for
example will cause an event transmission every time the door opens and closes.
The alarm thresholds can be configured to send email and text message notification
on just a single state, like the door being opened, but the transmission will occur
every time the door is both opened and closed. In cases where the state changes
often, many extra transmissions will be sent. In some cases, this can be enough
data to affect the subscription fees.
Installation
The antenna is a 1 meter whip antenna with no alignment required; however, an
open view of the sky is. Anything blocking the view of the sky can limit or totally
prevent communication with the satellite network. Trees, buildings, overhangs, and
canyon walls are some examples of obstructions that will limit performance. If only a
partial view of the open sky is available, latency times may increase but
communication can still be possible. Satellites are constantly passing overhead and
eventually one will come into view in even a small open space. However, this can
dramatically increase the latency time and if the satellite goes by too quickly, there
may not always be enough time to transmit the data, resulting in gaps in data. The
widest possible view of the sky will always produce the best results.
The SIT65 is provided with the necessary hardware for mounting the enclosure and
antenna to a wall or on a 2” pipe. For best performance, the antenna should be