Interface between SSI and RR

[kannati]

Thanks to Dorothy and PJW for providing more information about interface between two interlocking boundaries (SSI & RRI). If you provide more information i.e cross boundary track issues at relay controlled signals approaching SSI areas and vice versa is much appreciated.

Many Thanks

Kannati

Thanks to PJW for sorting out the thread.

To continue
The SSI Signal TFMs are used with the interface relays explained above, and they're generally put together in an interface loc or REB at the fringe, but it can be wherever is most convenient.
The most obvious functions (inputs and outputs) required are
1) lamp proving and aspect sequence related functions (EC/HR/HHR equivilent)
2) tracks clear and/or occupied, especially at the boundary, but further tracks may be required to indicate trains approaching.

If you look at some of the SSI Data Preparation standards you will find some detail about the functions that are most frequently used - have a look at SSI8003-51 (off the top of my head 51B and parts of 51D) The figures illustrate how it is all achieved.

There will often be additional complications - one I'm dealing with now is Axle counters because a lot more information is needed in connection with the Axle Counter reset/restore and Aspect Restriction.