Siemens SIMEAS Q80 Operating Instruction page 117

10.3.1.4 NTP Network Time Protocol
The Network Time Protocol (NTP) is a standard for synchronizing clocks in computer systems and uses the
connectionless transport protocol UDP. It was specially developed to enable reliable timing via networks having
variable package runtimes.
Precision: NTPv4 can keep a local system's time via the public Internet at a precision of 10 milliseconds; in local
networks under ideal conditions, precision levels of 200 microseconds and even better are possible.
Duration of synchronization process: Synchronization on an NTP server is a lengthy process. At intervals of 64
seconds, SIMEAS Q80 7KG8080 exchanges a data package with the server. Initially, 4 x64s are needed to set the
clock, after which the clock is synchronized at 64s intervals. It can take up to 3 h to reach precision in the range of
20ms. In order for the synchronization to begin upon activation, the measurement device must be set to use NTP
by default.
SIMEAS Q80 7KG8080 supports up to two NTP servers. For setting NTP, the following parameters are needed:
· selection of the time zone
· observance of the daylight saving's time transitions
· IP of the NTP server (1)
· IP of the NTP server (2)
Note
The synchronization between devices synchronized with NTP (see
Separate synchronization of all devices.
However, it is not possible to determine it.
If the phasing between two voltages in different devices is to be compared, only the Master is
to be synchronized to NTP. This synchronizes additional devices via DCF77, see
LAN in Master/Slave setup
To reduce the time needed for synchronization, the standard synchronization signal should be
defined with the device properties (see system manual section 4.1.2.2.2)
Connections and Conditioning
) is within approx. 10ms in the best cases.
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Power Quality Recorder SIMEAS Q80 7KG8080, Operating instruction
NTP time via LAN under
NTP time via
E50417-B1074-C419-A2, Release 09.02.2011
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