Installation and Maintenance Manual - Aastra 5000 AMT/PTD/PBX/0058/4/6/ENDescription et caractéristiques d’un PBX 01/2011 Page 101When a reference clock is no longer valid, the oscillator is set on:• An average of the last values stored• After reset, a value programmed at the factory.The number of the expansion card generating the reference clock is stored by theoperating software.3.8.4.2 Management of the master/slave mode (multisite network)For a multisite network with DECT base stations, the various Aastra XS/XL/XD iPBXsrequire the same synchronisation signal.Nota : The AXS12 iPBX allows multi-site DECT synchronisation through the wiring of athird pair on the base stations.In this case, DECT synchronisation is provided by one iPBX to the others; it can also beduplicated if two iPBXs have a digital connection to the RTCP.Nota : One of the 2 has priority; apart from these 2 iPBXs, all the other iPBXs in theAastra XS/XL/XD range can only receive the synchronisation. The UCVX cardhas a synchronisation port which can work in Priority Master mode (only one inthe network), Non Priority Master mode (only one in the network) or Slave mode.The primary ports of the two Master cabinets exchange status signals which enable aninternal logic to select the Active Master iPBX that provides synchronisation to the multi-sites, and the Passive Master iPBX which acts like a Slave iPBX.For an Aastra XD, the synchronisation ports are available on the IUCV-D card.The synchronisation ports of the two UCV-D cards are wired at the same time on the twoIUCV-D connectors. Clock signal validation, both for the primary port and the secondaryport, takes place only on the active card.Here, the primary synchronisation port provides the bit clock and the DECT multiframeclock.Nota : The DECT base stations connected to the integrated S0 accesses of the EXT1-Sand EXT1-S12 cards are synchronised (management of the M bit in the Sframe).By default, ex factory or after total reset, the iPBX is configured for operation in Masterand Non Priority mode. These 2 parameters which set the operating mode can beconfigured from the operating console (see Section1.3 , Document 6). Their current statusis stored in the iPBX and locked.
