NT_SetTimeToRTCTime

This functionality is not available in the PLC runtime system under Windows CE!

The function block "NT_SetTimeToRTCTime" can be used to synchronise the local Windows system time (displayed in the task bar) with the real-time clock of the PC (RTC time in the BIOS).

Remarks

When the function block is called the real-time clock of the TwinCAT PC is compared with the local Windows system time, and the local Windows system time is corrected based on the difference that was determined. Time zones and daylight-saving/standard time bias (difference) are considered. Please note that the correction can lead to time jumps during measurements or log book entries.

When the local Windows system time is set the operating system also automatically sets the RTC time to the new local Windows system time. Due to the conversion and delay the new RTC time is inevitably subject to a small error in the millisecond range, i.e. each time NT_SetTimeToRTCTime is called a small error is introduced in the real-time clock. In order to minimise deviations over a prolonged period, the compensation should be carried out every 24 hours, for example, rather than during each PLC cycle.

VAR_INPUT
    NETID       :T_AmsNetId;
    SET         :BOOL;
    TMOUT       :TIME := DEFAULT_ADS_TIMEOUT;
END_VAR

VAR_OUTPUT
    BUSY         :BOOL;
    ERR          :BOOL;
    ERRID        :UDINT;
END_VAR