User's Manual

ITC2100-NA Operation and Service Manual Version 1.0

Page 16 of 129

which then pass it on to Slave ITC's.

The Slave ITC's receive the alarm messages which were retransmitted for a particular

alarm ring. Instead of simply retransmitting as in normal mode, when the received messag-

es belongs to the assigned ring, the Slave ITC's also retransmit if the message is intended

for a higher ring and they have not already transmitted this message. Because in emergen-

cy mode the number of rings is higher (1 –16), this means that the message is also dis-

persed in subnetworks which contain a failed Master ITC's.

Example:

Assumption as shown in figure 4-3 below: The Master-ITC's in rural district B und C cannot

transmit time synchroned (link failure, time reference fault). The the message from the net-

work alarm controller only reaches the Master ITC in rural distrct A. This master ITC trans-

mits the alarm message with emergency information over the ring structure to its Slave

ITC's (). The Slave-ITCs in the other rural districts B and C, which border rural district A,

receive the signals via rural district A's Slave ITC's (++), as if the station were in an-

other ring. These Slave ITC's then retransmit the messages.

Information/Figure below:

 Rural district B has the situation that all Slave ITC's in ring 1 can "hear" Master A. Some of the

Slave ITC's in ring 2 can also "hear" Master A, but ignore the message because it is intended

for ring 1. The alarm in rural distruct B is put through as normal in rings which means that the

alsm is distributed first of all in ring 1 and then to the Slave ITC's in ring 2.

 Rural district c has the situation that not all the Slave ITC's in ring 1 can "hear" Master A. The

Slave ITC's in ring 1 which can receive the message from Master A transmit the alarm mes-

sage to Slave ITC's in ring 2 and also to the Slave ITC's in ring 1 which could not "hear" directly

from the Master. In this way all Slave ITC's which had not "heard" the forward the message.

Fig. 4-3: Emergency operation in a Multimaster wave network

Landkreis B

Master

Landkreis A

Landkreis C







