AMT/PTD/PBX/0058/4/6/EN Installation and Maintenance Manual - Aastra 5000Page 94 01/2011 Description et caractéristiques d’un PBXThis matrix routes the messages received over a PCM link, called a junction, to anotherexpansion card or module on the main card, through another internal PCM link.Each junction includes 32 Time Slots (TS) which are each used to route one voicemessage or digitised data.Certain TSs of a specific junction are assigned to the various subassemblies of the iPBXconnected to the matrix.The TSs are exchanged between the various subassemblies of the iPBX over asynchronous bus.3.8.1.2 Duplex and start logic function (Aastra XD only)Duplex logicThe main function of the duplex logic is to determine which of the two UCV-D cards of aduplex system is active (see Section 3.8.2). It consists of:• An exclusion hardware logic which guarantees that only one of the two cards can beactive at a given moment• Commands (Normal/Maintenance, Start/Stop) and indicators (Operational, Active, Outof service) on the front panel.• Command and status registers.Both cards exchange status signals, enabling them to know each other’s status.StartingA card can only start, in the application sense of it, when its status changes to “Active”.After the cabinet is powered on, the UCV-D card runs start-up tests. The behaviour thenvaries, depending on whether the system is simplex or duplex:• In simplex mode, the status of the UCV-D card changes immediately to “Active”.• In duplex mode, the status of the UCV-D card changes to “Active” if it is not out ofservice and if the other UCV-D card is not itself “Active”.3.8.1.3 Signal processing functionThe signal processing function is ensured by a module on the main card, and comprises:• generation of music on-hold,Nota : Music-on-hold can be replaced by external music. The level of external music-on-hold is stored in the memory of the UCV/UCV-D card, which- can beprogrammed using AMP.• Generating tone signals• Detecting tones• Sending and receiving multiple frequency signals
