Siemens siprotec 7SA522 - Page 121

2.4 Protection data interfaces and communication topology (optional)
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7SA522 Manual
C53000-G1176-C155-3
Figure 2-46 Distance protection topology for 3 ends with 3 devices - example
In address  /2&$/5(/$< you finally indicate the actual local device. Enter the
index for each device (according to the consecutive numbering used). Each index
from 1 to the entire number of devices must be used once, but may not be used twice.
Make sure that the parameters of the distance protection topology for the distance pro-
tection system are conclusive:
• Each device index can only be used once;
• Each device index must be allocated unambiguously to one device ID;
• Each device-index must be the index of a local device once;
• The device with index 1 is the source for the absolute time management (absolute
time master).
During startup of the protection system, the above listed conditions are checked. If one
out of these conditions is not fulfilled, no protection data can be transmitted. The
device signals ´'7LQFRQVLVWHQWµ (“Device table inconsistent”).
Device Logout A device can be removed from the topology via the receive signal 3484 ´/RJRXWµ so
that the remaining relays can still assume their protection function.
If a device logs out functionally (Functional Logout), the number of active protection
devices reduces. In this case the teleprotection schemes are automatically switched
from 3 to 2 end. If no remote end is available, ´'LV7&DUU)DLOµ is signalled.