according to the specs the master does indeed have to be on the end connector, and the slave on the middle connector. but in practice it doesn't really matter.
it's more important if there is only one device on the cable, in that case it should be master and should be on the end connector. but again, in actual fact things will ofter work in other configurations.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien