The Free On-line Dictionary of Computing (30 December 2018):

token bus

    (IEEE 802.4) A networking protocol which mediates
   access to a bus topology network as though it were a token
   ring.  This eliminates the collisions found in carrier
   sense collision detect protocols.  Nodes can be configured
   to pass the token in any order, not necessarily related to
   their physical ordering on the bus.  The token is sent from
   one node to its successor in the logical ring by broadcast on
   the bus and is ignored by the other nodes.

   (1996-12-13)