Description:
Common causes:
Last sync date is not equal last record GPS date.
Record GPS date is when record was generated according to GPS clock.
Last sync date is when server received last record.
Ideally, both dates are close to each other, as a record is sent shortly after being created and received by the server (from a few seconds to a few minutes difference depending on configuration settings).
However, for example when a device loses GPRS signal and cannot send newly created records, it stores them in the device and only sends them when signal is restored.
For example object is set to Maximum delay 01:00 in object settings and has not sent any record for a few hours due to lack of signal.
When it regains signal, it starts to send the oldest record first.
Despite records received being generated many hours ago, last sync date shown will still be the current local date and time, because it takes the date the record was received.
But device will be still be shown as No signal. Because record GPS generation date will still be many hours old and maximum delay is just 1 hour.
When we look at the raw data, we check the dates (shown in UTC format by default), which are 3 hours minus of local time:
This means record was created (Last Gps Datetime) at 10:08 local time but was received (Server Datetime) at 11:30 local time.
Since the current time is 11:30 local time and the last record received was created at 10:08 local time, this means 1 hour and 22 minutes of delay.
This is greater than the Maximum delay of 1 hour, thus the object will appear as No signal.
Device will be shown as online when server will receive record with generation date not older than the Maximum delay set in object settings.