Reference:Configuration/General/NTP
The device can synchronize its internal date/time to an NTP server using the SNTP protocol. Without synchronization to an NTP server the internal date/time is reset to Januar 1st, 1970 0:00 after each restart.
Configuration
Server | The IP-Adresse of the time server |
Interval [min]: | The time interval (in minutes) at which the device tries to synchronise with the time server |
Timezone | Select the time zone in which the device is located. |
String | If the timezone to be used is not one of the predefined timezones, it can be confugured with a string in accordance with the IEEE POSIX standard |
Last sync displays the data and time of the last synchronisation.
Timezone Configuration String
Time services always provide the coordinated world time UTC (Universal Time Coordinated), which corresponds to GMT (Greenwich Mean Time), not however the correct time zone and summer time. It is therefore possible to specify the time difference between the time zone and the world time in the String field. The difference from the time zone GMT+1 (Central European time zone) is 60 minutes. A further 60 minutes has to be added with summer time, adding up to a total difference of 120 minutes. In this case, however, you must adjust the time difference manually when switching from winter to summer time and vice versa.
If a so-called timezone string was entered in the String field, the device can make the switch from summer to winter time automatically. The name of the time zone, the name of the summer time zone, their respective differences in time compared to the UTC and the time switch points are encoded in this field.
There are various formats for the specification of this string. These formats are defined by the IEEE POSIX standard. POSIX timezone strings have the following format (optional parts in square brackets):
StdOffset[Dst[Offset], Date/Time, Date/Time]
Std stands for the time zone (for example, CET for Central European Time or MET for Middle European Time).
Offset specifies the time difference between the time zone and UTC, for example, -1 for Central European Time. The difference is negative if the time zone is ahead of UTC. If the time difference does not comprise full hours, the number of minutes can be added, for example, -1:30. The TZ string ends here if you are not using a summer time.
Dst stands for the summer time zone (for example, CEST for Central European Summer Time or MES for Middle European Summer Time).
The optional, second Offset parameter gives the offset of the summer time in respect of UTC. An hour before normal time is assumed if no entry is made.
Date/Time define the start and end of summer time. The format for a time entry is Mm.n.d, signifying the d-th day of the n-th week of the m-th month. Day 0 is Sunday. If the fifth week is entered, the last day (with respect to d) of the month is meant. The format for a time entry is hh[:mm[:ss]], in the 24-hour format.
Example
The Central European time zone is specified CET-1CEST-2,M3.5.0/2,M10.5.0/3:
CET (Central European Time) - offset -1
CEST (Central European Summer Time) - offset -2
Switch to Summer Time at 3(March), 5(last week of the month), 0(Sunday)/at 2:00
Switch to Standard Time at 10(October), 5(last week of the month), 0(Sunday)/at 3:00