Siemens SIMATIC S5-100U System Manual page 313

S5-100U
Tables 12-5 through 12-8 provide you with information about the significance of the signal states of
the respective flags.
Clock Flags
Table 12-5. Significance of Bits 0, 1, 2 and 3 of the Status Word
Bit Number Signal State
0
1
2
3
Operating System Flags
Table 12-6. Significance of Bits 4 and 5 of the Status Word
Bit Number
Operating
Status
Mode
Word
STOP 4
5
RUN 4
5
EWA 4NEB 812 6120-02b
1 Error in setting entry
0 No error in setting entry
1 12-hour clock mode
0 24-hour clock mode
1 Transfer settings
0 Do not transfer settings
1 The clock time can be read
0 The clock time cannot be read
Signal
State
1 The clock updates only words 0 to 3 (current time/date) in
the clock data area. You can set the clock by using the
FORCE VAR programmer function.
0 The clock does not update the clock data area. Words 0
to 3 contain the time at which the last switch from RUN to
STOP occurred.
1 Words 18 to 21 contain the time at which the last RUN to
STOP switch occurred or the time at which the last
Power OFF occurred if bit 4 is also set.
0 Words 18 to 21 are not used.
1/0 The clock continually updates the clock data area
(Words 0 to 17).
1 Words 18 to 21 contain the time at which the last switch
from RUN to STOP occurred or the time at which the last
Power OFF occurred.
0 Words 18 to 21 are not used.
The Integral Real-Time Clock
Meaning
Meaning
12-13