Abstract: A communications apparatus for switching among different interfaces includes a switch unit. The switch unit includes a main switch for switching data of a fixed length and an interface having a first buffer for an input of the main switch and a second buffer for an output of the main switch.

Abstract: A dual apparatus having a first unit and a second unit of a same configuration, one being operated in an active state while the other in a standby state. Each of these first and second units comprises a first selector for setting a current unit to the active state if a predetermined fault occurs in the other unit; a second selector for sending information indicative of the setting of the current unit to the active state, if a predetermined fault occurs in the other unit and the first selector selects a first act state, to the other unit and, setting the current unit to the standby state, if the predetermined fault does not take place in the other unit and the first selector selects the active state and a state indicated by information supplied from the other unit is the active state; and a register for holding one of the active and standby states selected by the second selector.

Abstract: A duplex memory control apparatus having a first control unit containing a first memory and a second control unit containing second memory, a first control unit and a second control unit connected to each other through a bus.

Abstract: An exchange equipment using STM able to achieve an improvement of an efficiency of use and an improvement of ease of increase of terminal cards, that is, an STM type exchange, including a time switch, for performing exchange processing of time division multiplexed data, wherein a ring highway is connected via a terminal common unit to an upstream highway and a downstream highway coupled to this time switch via a highway interface unit or directly and wherein a plurality of terminal cards are connected to this ring highway. Each terminal card is provided with an add/drop unit which drops and adds the data from and to an assigned time slot on the ring highway according to control information indicating time slot assignment information determined by the control unit and adds the data and with a card control unit which controls the add/drop unit.

Abstract: A communications apparatus for switching among different interfaces includes a switch unit. The switch unit includes a main switch for switching data of a fixed length and an interface having a first buffer for an input of the main switch and a second buffer for an output of the main switch.