Meinberg TCR511 - Manual (Page 16)

16
DCF Simulation
The DCF_MARK output ( TTL ) produces a time mark signal similar to the signals
transmitted by the german VLF time code transmitter DCF77. Within one minute a
complete time code frame is transmitted. Since there are no timezone and leap second
announcements in the IRIG time code, these announcement flags (daylight saving flag,
leap second flag) are neglected. The generated DCF telegram always contains the time
information which is derived from the IRIG Signal and the system clock. When
receiving a time code telegram containing a leap second ( field sec. is 60 ) the DCF
simulation is turned off for a minute. By this the re-synchronization of all clocks
connected to the simulation outputs is enforced. The issued DCF time code frame
contains a date information which is derived from the system clock. The validity of the
system clock date is ensured by a 'day of year' comparison. In case of an invalid system
clock date the DCF simulation is turned off. System clocks initial date can be set via
COM0. In case of brown out or power failure a lithium battery guarantees the system
clocks operation for at least ten years.
M Start of Minute (0.1 s)
R RF Transmission via secondary antenna
A1 Announcement of a change in daylight saving
Z1, Z2 Time zone identification
Z1, Z2 = 0, 1: Daylight saving disabled
Z1, Z2 = 1, 0: Daylight saving enabled
A2 Announcement of a leap second
S Start of time code information
P1, P2, P3 Even parity bits
0
10
20
30
40
50
R
M
1
4
2
1
20
10
8
4
2
1
P
2
20 10 8 4 2 1
2
4
8
10
1
2
4
8
10
2 0
4
0
8
0
P
3
A1
Z1
Z2
A2
S
1
2
4
8
1 0 2
0 4
0 P
1
Minute
(reserved)
Hour
Day of Month
Day of Week
Year of the Century
Month of Year