Technical data

13.2 How the Clock Functions
The clock can have the following statuses:
Description of the status transitions
1. When the CP starts up, the hardware clock of the CP 5430 TF/CP
5431 FMS is checked.
2. The status of the hardware clock was recognized as invalid. The clock
must be reset.
3. The status of the hardware clock was recognized as valid, i.e. the
hardware clock has already been set.
4. If during the CP start-up the clock is recognized as valid, the CP auto-
matically assumes the "clock_slave" status.
Start-up
Clock
valid
= "invisible" CP operating statuses
= "visible" CP operating statuses
Power
OFF
Clock
invalid
Clock
slave
Clock
master
1
3
2
4
5
6
7
8
9
Fig. 13.3 Clock Statuses
Clock Services C8976060/02
Volume 1 13 - 6