Abstract: An adapter No (n-1) propagates a daisy-chained grant signal directly to the adapter No (n) and a by-passed grant signal to the adapter No (n+1) case. The adapter No (n) is responsive to the status of the previous adapter in the chain, for determining which of the regular grant signal ("GR") or by-passed grant signal ("GRA") has to be taken account of by the succeeding adapter, when the latter wants to access the transmission bus (11). Further, the adapters connected to the chain may be partitioned into groups (80) within which the grant signal is distributed in parallel to the adapters, and propagated to the next group only when none of its adapters (10) requests access to the transmission bus. The same priority level is given to each adapter or group of adapters connected to the daisy-chain, and permits said chain to remain operative even when several adapters are unplugged or malfunction.