Copyright © Sigicom AB 2020
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6.3.
GPS time synchronization
This function makes it possible to use two C22:s to measure the ground
wave speed from a blasting or a train, and is enabled in the Monitoring
config menu (see 5.8.1). When enabled, the C22 detects and stores current
time difference
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in order to get exact time for each transient. It is
recommended that the two C22:s are placed with a distance of at least 50
meter between them, and that their Trigger level is so low that they
triggers a transient each. Please contact Sigicom for further details of
using this function.
6.4.
Time Synchronization through Internet
The C22 automatically synchronizes its clock to an NTP (
N
etwork
T
ime
P
rotocol) server on Internet. SNTP according to RFC 4330 is used. No
user configuration of the NTP server can be made.
An NTP request with subsequent difference calculation is performed at
every INFRA Net communication, but not more often than once every 60
minutes. The calculated difference is stored with each data timestamp.
The internal clock is gradually adjusted while monitoring is running. Any
remaining difference is adjusted at power off.
Expected time diversion is below 1 minute per month.
Note! All data from C22 is always time stamped with UTC time. Time
zone only affects the presentation of time.
6.5.
Daylight Saving Time
Automatic transition between daylight saving time (DST) and standard
time (STD) is configured with the time zone mentioned above. The C22
does not need to turn monitoring off during the transition.
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this time difference is defined as:
(internal C22 time) – (exact GPS time)