Users Manual

https://www.lairdconnect.com/iot-devices/iot-
sensors/sentrius-bt7x0-tracker-multi-sensor
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The BT710 tracker is designed to log data from other compatible tracker devices it observes during its BLE scan operations.
The following diagram (Figure 5) shows the data logging timeline and how various parameters affect each logging phase.
Figure 5 - Data logging timeline
As a tracker detects remote trackers (“remotes”) in each BLE scan, the discovery database is updated and the remote steps
through three phases throughout a single Contact Period.
▪ Discovery Phase – Remote trackers are tracked in a RAM-only discovery database for each scan they are detected.
Once the total detection time is greater than the configured Discovery Duration, the records for the remote are committed
to a Flash-based log and the remote enters tracking phase. If a remote is only detected fewer scan intervals than the
configured Discovery Duration within a given contact period, they are cleared and not logged to Flash. This is useful for
situations where trackers are in proximity for very brief periods of time and do not warrant storage to the Flash-based log.
▪ Tracking Phase – Remote trackers in the tracking phase get an additional record in the Flash-based log for every scan
interval they are detected, up to the maximum records that can be recorded for the duration of the tracking phase (set by
the Tracking Duration parameter).
▪ Untracked Phase – If a remote tracker has been detected for the entirety of the Tracking Phase, no more records are
made for that remote until the Contact Period expires. This way, a single remote only takes up a maximum number of
Flash log records determined by the Tracking Duration each Contact Period, allowing remaining Flash space to be used
for detection and logging of other remote devices during that Contact Period.
The BT710 tracker can store up to 350 log entries within a 24-hour contact period. Each log entry can store 15 records for a
remote tracker, one per scan interval. The number of unique remote trackers that can be logged is a function of the Scan
Interval and Tracking Period parameters. For example, with tracking period of 15 minutes, up to 350 unique remote devices
can be tracked if scan interval is set to 30 seconds. The following data is logged from the remote tracker’s advertisement data:
Figure 6 - Data logged for each remote tracker detected in BLE scans
0TIME (SECONDS) 30 60 90 120 330270 300
REMOTE TRACKER
DETECTED IN SCAN
Scan Interval
30 Seconds
Discovery Duration
300 Seconds
Tracking Phase
Starts
(Flash-based Logging)
1770 1800
Tracking Duration
1800 Seconds
1830 1860
Logging Timeline for Each Remote
Tracker Starts on First Detection
(RAM-only Logging)
1890 1920 1950
Untracked Phase Starts
(No Logs Recorded for This Remote
Tracker Until Next Contact Period)
86,370 86,400
Contact Period
86,400 Seconds (1 Day)
Logging Timeline Resets
After Contact Period Expires
Scan Duration
2 Seconds
DISCOVERY PHASE TRACKING PHASE UNTRACKED PHASE
Device ID Timestamp Status RSSI Motion Status TX Power