BOS_bank_FTRA (primitive dataflow)
  *Forward MWPC trigger bank: gives multiplicity and roads.

   word  #    type    content
-----------------------------
         1    B32     decision bits
         2    B32     roads along R for phi sector 0
         .     .
        17    B32     roads along R for phi sector 15

        18    B32     multiplicity per phi sector
        19    B32           low bit address = 4 4*iphi+3 iphi = 0,15

        20    B32     number of overflows
        21    B32     total multiplicity
        22    B32     topological pattern code for FMWPC