YSI Level Scout - Manual (Page 27)

3.3.2 ALARM SCANNING METHOD AND BROADCAST
The frame labeled Alarm Scanning Method allows the user to establish alarm and warning pressure limits(figure 3.31). When alarm
scanning is enabled, if the pressure reading exceeds either of the Hi limits or is below either of the Lo limits the Alarm Scanning
Method will be initiated, overriding the current active scan method. The Alarm Scanning Method may be optionally configured to
use a different logging rate from the previous scanning method that was active. This is useful to obtain faster samplings should an
unusual (outside of normal ranges) event occur. Note that both the normal and alarm data are stored within the current logging test
profile.
Figure 3.31
Warning
When using alarms (with or without broadcasts) make sure the normal logging period of the active test profile
is not too long. The transducer only checks the measurement for an alarm condition at the moment the
logging event is made. Short transients could be missed or sustained changes could be reported late by up to
one normal logging period. For example, if the normal logging period is set to 15-minute intervals, the
transducer only checks for an alarm condition once every 15 minutes. Once an alarm condition occurs the
transducer can use the optional alarm scanning logging period (normally faster).
To enable the Alarm Scanning Method select the Enable Alarm Scanning check box. Next, enter the high and low level alarm and
warning values in the provided input boxes. If only a single alarm/warn level is required (not a separate warn limit and alarm limit),
the same value should be entered for the warn and alarm input boxes. If an alternate Alarm Scanning Method scan rate is desired,
enter the scan period in the Period input box. A logging period of 0_0:0:0 will cause the transducer to use the existing logging period
of the test profile that was running prior to the Alarm Scan Method.
Tip
The Alarm Scanning Method is frequently used with the Broadcast option described in the following section.
The frame labeled Broadcast (figure 3.32) enables the transmission of autonomous data packets from the Level Scout. Autonomous
data is data that automatically transmits, without user requests. The unit can be configured to autonomously broadcast normal
logged data packets, alarm logged data packets only, or both normal and alarm logged data packets. In either case, the Level Scout
will broadcast the requested data items immediately after logging them to its internal data logging memory.
Figure 3.32
YSI Incorporated Level Scout 25