7 Time Synchronization
7.1 General
130
SICAM I/O Unit, 7XV5673, Device Manual
E50417-H1040-C484-A3, Edition 05.2012
7.1
General
During operation, SICAM I/O Unit needs the date and time for all time-relevant processes. The term
time
is
used throughout this section to refer to both the date and the time.
The time synchronization in the SICAM I/O Unit is necessary to guarantee a common time basis for the com-
munication with peripheral devices and time stamping of the process data.
SICAM I/O Unit supports both external and internal time synchronization. The type of time synchronization is
specified during the parameterization (see chapter 6.3.3.5).
7.2
Internal Time Keeping
7.2.1
Time Format
The internal time is kept in UTC (Universal Time Coordinated) from 01.01.2000, 00:00 to 31.12.2099, 23:59.
To display the local time for example on the HTML pages of the user, you can configure a local time correction
factor and the automatic adjustment to daylight saving time during parameterization (see chapter 6.3.3.5).
7.2.2
Status Bits
FAIL Status Bit
The
FAIL
status bit implemented in the SICAM I/O Unit signals with "0" that the time is
valid
and with "1" that
the time is
invalid
.
The status of the FAIL bit corresponds to the "Clock error" operational indication, see chapter 12.
The following table lists the time stamps of events or indications for the displayed operational and error logs
according to status bit set/not set using the example of
date 2007-09-26, time 13:49.35246
:
Table 7-1
FAIL Status Bit for Time Synchronization via NTP Server
DST Status Bit
With "1", the
DST
status bit implemented in the SICAM I/O Unit signals that the local daylight saving time is
active. The operational indication "Daylight saving time" is displayed.
FAIL
Output
0
2010-09-26 13:49.35:246
1
2010-09-26 13?49?35?246
NOTE
When time output contains “?”, there will be no time synchronization. In this case, first of all, parameterize the
Source of the time synchronization
“
Internal
” and afterwards the desired time synchronization source again.
MAN_SICAM_IO-Unit_7XV5673_US.book Page 130 Thursday, May 10, 2012 10:59 AM