I assume that TdFrRmLoc and TdtoRmLoc are the From- and To- locations. So they are two different things. That means you can't join both fields to one LocationMaster table directly. You can do several things.
Use a mapping table to add LocTyp (and perhaps LocDesc) to the Txnd table for both From- and To- locations.
Create two LocationMaster tables, one for From- locations and one for To- locations
Create a link table
Use LocationMaster as a data island and don't associate it with Txnd. Use field triggers make selections.
Option 2 is the easiest to do:
LocCd as TdFrRmLoc,
LocCoCd as LocFromCoCd,
LocDesc as LocFromDesc,
LocTyp as LocFromTyp
LocCd as TdToRmLoc ,
LocCoCd as LocToCoCd,
LocDesc as LocToDesc,
LocTyp as LocToType
Option3 is fairly easy too and gives you a bit more flexibility:
TdRmSz, //assuming this is the primary key of Txnd, if not replace it with the field that is