Campbell Scientific AL200 ALERT2 Encoder, Modulator, and Sensor Interface - Manual (Page 21)

AL200 ALERT2 Encoder, Modulator, and Sensor Interface
Under normal operation, the AL200 will obtain a GPS fix and measure sensors
based on its configuration. When the sensors are measured and an event
threshold has been exceeded, the AL200 will wait until its designated time slot
and then power up the radio and transmit the data to a repeater or base receiver.
• Concentrated ALERT data is retransmitted using the ALERT
concentration protocol.
• Event-driven rainfall data is transmitted as a tipping bucket rain gauge
report with a sensor ID of zero (0).
• Other event-driven sensor data is transmitted as a general sensor
report. If events for multiple sensors are detected in the same frame,
then multiple general sensors reports will be transmitted.
• A scheduled self-report is transmitted as a multi-sensor report.
If a GPS fix cannot be obtained and the AL200’s internal clock cannot be
disciplined, the device will transmit data during random slot times throughout
the frame interval in an attempt to not continuously interfere with adjacent time
slots.
When connected to the AL200 with the Device Configuration Utility, the
AL200 will power up and measure the attached sensors on the Configuration
Sensor Scan Interval located on the Sensor Data Monitoring tab, but
transmissions will be suppressed.
9. Maintenance
It is a good idea to periodically check the sensor inputs against known values to
ensure that the device is still within the specified accuracy ranges. Connecting
to the AL200 with a USB cable will force the AL200 to measure the attached
sensors on the Configuration Sensor Scan Interval. This will allow the user
to quickly see how sensors respond to changes. Upon disconnecting from the
device, the AL200 will resume its Sensor Scan Interval.
Pressing the test button for three to six seconds will trigger a test transmission
containing the latest data available to the AL200. Pressing the button for
longer than six seconds will cause the AL200 to generate a test tone and sustain
it for five seconds. This test tone can be used to check the forward and
reflected power of the radio.
Consult your sensor and radio manufacturer’s manuals for recommended
maintenance of these devices.
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