Siemens Simatic S7 Series

Program instructions
7.2 Clock
S7-200 SMART
System Manual, 09/2015, A5E03822230-AC
169
T byte
Description
Data value
15
DST ending month
1 to 12 (BCD value)
16 DST ending day 1 to 31 (BCD value)
17
DST ending hour
0 to 23 (BCD value)
18 DST ending minute 0 to 59 (BCD value)
The following bytes 9-20 are used only for correction mode = EEH (extended user assigned)
9
DST correction hours
0 to 23 (BCD value)
10
DST correction minutes
0 to 59 (BCD value)
11
DST beginning month
1 to 12 (BCD value)
12
DST beginning week
1 to 5 (BCD value)
5
13
DST beginning weekday
1 to 7 (BCD value)
14
DST beginning hour
0 to 23 (BCD value)
15
DST beginning minute
0 to 59 (BCD value)
16
DST ending month
1 to 12 (BCD value)
17
DST ending week
1 to 5 (BCD value)
5
18
DST ending weekday
1 to 7 (BCD value)
19
DST ending hour
0 to 23 (BCD value)
20
DST ending minute
0 to 59 (BCD value)
1
EU convention: Adjust time ahead one hour on last Sunday in March at 1:00 a.m. UTC. Adjust
time back one hour on last Sunday in October at 2:00 a.m. UTC. (The local time when the correc-
tion is made depends upon the time zone offset from UTC).
2
US convention: 2007 standard - Adjust time ahead one hour on second Sunday in March at 2:00
a.m. local time. Adjust time back one hour on first Sunday in November at 2:00 a.m. local time.
3
Australia convention: 2007 standard - Adjust time ahead one hour on first Sunday in October at
2:00 a.m. local time. Adjust time back one hour on first Sunday in April at 2:00 a.m. local time (also
for Australia - Tasmania).
4
New Zealand convention: 2007 standard - Adjust time ahead one hour on last Sunday in Septem-
ber at 2:00 a.m. local time. Adjust time back one hour on first Sunday in April at 2:00 a.m. local
time.
5
To assign the last occurrence of the weekday in the month (for example, the last Monday in April),
set the week = 5.
Extended power outage effect on the CPU clock
See the S7-200 SMART system manual appendix A CPU specifications, for how long the
real-time clock can maintain the correct time during power outages.
A CPU initializes with the time values shown in the following table, after an extended power
outage.
Date
Time
Day of week
01-Jan-2000
00:00:00
Saturday