Page 484 - IRSEM_Main Book

Two evaluators (EVs) (M&R) are provided in each AG as well as adjacent stations. The
main DPS of UP and DOWN direction are connected to EV(M) and redundant(R) DPs of
UP and DOWN direction are connected to EV(R). The MSDACs used in the present
scheme have one dedicated COM-AdC board with ethernet port to communicate with
adjacent EVs. The evaluated information from COM-AdC is transferred through it’s
ethernet port to dedicated OFC, via an unmanaged ethernet switch as shown in Fig.4.
The COM-AdCs of both M & R EVs are hot linked and any failure of one of the board
does not hamper the track detection.

Fig 4. Interconnection of EV with OFC via COM

The ethernet switch used in Fig.4 is as shown below

Chapter 20: Automatic Block Signalling Page 430 of 535