YSI Data Scout - Manual (Page 18)

3.4.2 CONFIGURE ALARMS AND BROADCASTS
Click the Alarms and Broadcast button (Figure 3.25) to access the ‘Alarms and Broadcasts’ window (Figure 3.26). Alarm and broadcast
features are available for configuration. An alarm is simply an indication that some pre-determined measurement boundary has been
exceeded. An Alarm Limit is configured as a high and low level band within which all readings are expected to fall. If a measurement
value falls outside of the defined band, then the alarm condition is met and the alarm action is initiated.
Figure 3.25
Figure 3.26
To enable the Alarm and Broadcast function, check the Enable Alarm Checking box at the top of the form. When enabled, Alarm
Checking only occurs during an active test (Tests tab). Set the Alarm and Warning High and Low levels to the desired value. To disable
a specific high limit, set it higher than the transducer can read (example, 9999). To disable a particular low limit, set it lower than the
transducer can read (example -9999).
The transducer’s scan interval may be changed to a different interval during an alarm condition. To change the scan interval during an
alarm condition, set the Alarm Scan Interval to the desired scan interval. To maintain the active test’s scan interval as set in the Test
tab, set the Alarm Scan Interval to all zeros.
The two boxes near the bottom of the Alarm form enable/disable broadcasting. Alarm Checking can be specified with or without
broadcasting. Broadcasting can be used to communicate Level Scout scans to a third party device that is connected to the cable. When
Broadcast Normal Logs is enabled, all scans are broadcasted to the third party device. Special three letter normal codes begin these
messages (see first four entries in Table 1 below). Note that the Enable Alarm Checking does not need to be enabled for these messages
to be broadcasted. When Broadcast Alarm Logs and Enable Alarm Checking are enabled, only scans that meet alarm conditions are
broadcasted to the third party device. These messages begin with a three letter alarm code (see last four entries in Table 1).
If only Enable Alarm Checking is enabled and neither of the two broadcast are checked, then the only way to determine if an alarm
condition is happening is to manually poll an Active test’s status with the refresh button on the software.
Important: Broadcasts should be used with caution as they interfere with the normal communications between a transducer and its
controlling PC using SDI-12 protocol. For this reason, Data Scout and Data Scout Mobile always operate each transducer with
broadcasts disabled. Factors that should be considered when selecting a scan interval for broadcast data include the possible duration
of an alarm event and whether the expected rate of change warrants the data rate specified. Both normal scan interval and alarm scan
interval must be kept long enough to allow for transducer communication between broadcasts. Thus, setting either interval shorter
than 10 seconds is impractical when broadcasting is uses.
Alarm Code Code definition
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