Siemens 6MD662, Руководство пользователя

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Redundant PROFIBUS DP interface
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SIPROTEC PROFIBUS DP - Bus mapping 6MD662/3/4
C53000-L1840-B011-03
1.6 Redundancy behavior
1.6.1 Redundancy start-up
After switching on or reset the SIPROTEC device and after the bus specific parame-
ters and data assignments were transferred to the PROFIBUS DP modules (ref. to
chap. 1.3.1.1), the redundant slave is in the redundancy start-up.
During the redundancy start-up, the slave interfaces have alternating the state
S_PRIMARY and S_WAITING. The module on port B always starts with S_PRIMARY
and the module on port D with S_WAITING.
A start-up timer with the time Tsprimary is started on the module which has the
S_PRIMARY state.
After expiry of Tsprimary, a switchover of the redundancy state is executed via Red-
Com communication (ref. to chap. 1.2).
The module, which now became S_PRIMARY, starts again the start-up timer and a
further redundancy state switchover will be executed after Tsprimary expires.
Tsprimary starts at 2 s and is increased by 2 s after each state change until the con-
figured maximum value TsprimMax.
TsprimMax can be selected during set up of bus specific parameters in DIGSI (ref. to
chap. 1.3.1.2).
It is the aim of this procedure to make the decision which module becomes PRIMARY
first.
Only if the following prerequisites are fulfilled, the redundancy start-up will be finished
and a module becomes the PRIMARY one:
•
The PROFIBUS DP communication start-up between the master device and the
slave interface was completed successfully. Master and slave are in data
exchange.
•
The PROFIBUS DP master is PRIMARY and it sends the PRIMARY state via
“Control_O_1” to the slave interface (ref. to chap. 1.4.1.4).
•
The PROFIBUS DP module currently has the state S_PRIMARY.
An (simplified) example for a redundancy start-up is shown in Figure 1-11.
As the result in this example the PROFIBUS DP module on port D becomes
PRIMARY and the module on port B becomes BACKUP.