Sutron Corporation X-Link Operations & Maintenance Manual, Rev 1.63 5/24/2016 pg. 123
12.
Time Keeping
To keep time, X-Link uses an RTC (real time clock) backed by an internal battery.
The RTC keeps ticking even if the main battery to the X-Link is removed. The RTC
will, at worst case, drift ±2 minutes per month (0 to +50C). The lifetime of the
RTC battery is about five years.
Each X-Link has its time set when it leaves the factory.
X-Link time can be viewed and set via LinkComm and via command line.
12.1.
Iridium
IRIDIUMLink unit automatically synchronizes its time to the Iridium system after
every transmission.
Prior to version 1.48, the sync would happen only once a day.
Use the Local Time Offset to convert the time from UTC to a local time zone. The
change will take effect after the next good transmission.
12.1.1.
Time Change
When its clock is changed, X-Link logs the time before the change and the time
after the change to its log. If the clock is changed by more than 15 minutes, X-
Link resets itself to ensure correct future operations.
Here is logged data following a significant time change:
01/24/2012,09:10:26,Time Before Change
01/24/2012,08:52:00,Time After Change,-1106
01/24/2012,08:52:02,Reset Soft,1
That logged data means that a time change happened when the clock read
09:10:26. The new time was 08:52:00, with the clock being turned back 1106
seconds. Since the clock change was significant, the system reset itself after the
change.
12.1.2.
Iridium Epoch Change
All IRIDIUMLink units must be upgraded to version 1.48 by May 11 2014. If they
are not upgraded, their clocks will become incorrect, due to the Iridium epoch
change. Is it sufficient to upgrade the unit to 1.48 or newer to avert the issue -
no other changes are needed.
