This Driver can be configured to handle or ignore the SU flag of timestamps. This flag, when configured, that is, equal to 1 (one), indicates that a timestamp is in daylight saving time.

To configure the handling of daylight saving time by this Driver, configure the Timestamp SU Flag (Summertime adjustment) option of the Timestamp group on the Properties tab of this Driver's configuration window with the following values:

•Ignore (default value): Ignores the SU flag of timestamps received and sent and ignores the computer's daylight saving time configuration. Warning messages are generated in the log whenever this Driver detects timestamps with the SU flag non-consistent with the computer's daylight saving time:

•When receiving an incoherent timestamp: The message is "Warning: driver is ignoring mismatching summertime configurations on the PLC (<PlcBias> minutes) and on the server (<LocalBias> minutes). The resulting timestamp may be incorrect!"

•When sending an incoherent timestamp: The message is "Warning: the driver is configured to ignore the summertime flag, but the system currently is operating on summertime (<LocalBias> minutes). The outgoing timestamp may be incorrect!"

•Automatic: Handles the SU flag of timestamps received and sent and considers the computer's daylight saving time in the following way:

•When receiving a timestamp with the SU flag equal to 1 (one) and if the computer is not in daylight saving time, delays the timestamp in one hour

•When receiving a timestamp with the SU flag equal to 1 (one) and if the computer is in daylight saving time, does not change the timestamp

•When receiving a timestamp with the SU flag equal to 0 (zero) and if the computer is not in daylight saving time, does not change the timestamp

•When receiving a timestamp with the SU flag equal to 0 (zero) and if the computer is in daylight saving time, brings the timestamp forward one hour

•When sending a timestamp, if the computer is in daylight saving time, the SU flag is equal to 1 (one)

•When sending a timestamp, if the computer is not in daylight saving time, the SU flag is equal to 0 (zero)

•In cases when the computer is in daylight saving time but the daylight saving time configuration is not standard, that is, the bias is different from 60 minutes:

•When receiving a timestamp with the SU flag equal to 1 (one), delays the timestamp in one hour, assuming that in the device the daylight saving time bias is always 60 minutes, and adds the computer's daylight saving time bias

•When sending a timestamp, delays the timestamp according to the computer's daylight saving time bias and send the timestamp with the SU flag equal to 0 (zero)

•In cases when the timestamp is adjusted, a message is generated in the log informing:

•When a received timestamp is adjusted: The message is "Timestamp adjusted: From PLC (<PlcTimestamp> [<PlcBias> minutes]) to Driver (<LocalTimestamp> [<LocalBias> minutes])"

•When a timestamp is adjusted for sending: The message is "Timestamp adjusted: From Driver (<LocalTimestamp> [<LocalBias> minutes]) marked as *summertime*" or "Timestamp adjusted: From Driver (<LocalTimestamp> [<LocalBias> minutes]) to PLC (<PlcTimestamp> [<PlcBias> minutes])"