3-13810-A2-GB30-30 September 1998Model 3811 InstallationOverview 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Model 3811 Installation 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Removing and Replacing Model 3811 Modems 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .OverviewThe carrier-mounted Model 3811 modem (Figure 3-1)is capable of dial or 4-wire/2-wire leased-line operationand installs into a COMSPHERE 3000 Series Carrier. TheModel 3811’s faceplate has 16 LED status indicators fordisplaying modem activity and an audio speaker jack forthe carrier’s optional speaker.The Model 3811 modem’s rear has two DTE edge cardconnectors that mount into a connector plate located onthe rear of the carrier. This connector plate has twoDB-25-S connectors, one providing an EIA RS-232 DTEinterface and one providing an EIA RS-366A DTEinterface. The Model 3811 derives ac power from theCOMSPHERE 3000 Series Carrier’s backplane which is acommon bus to all devices installed in the carrier. Theuser interface to any Model 3811 is through the shareddiagnostic control panel (SDCP), an optional featuresimilar to the DCPs on the Model 3810 and Model 3820.For a better understanding of DCP operation, refer toChapter 4, DCP Operation.The COMSPHERE 3000 Series Carrier has a total of17 slots. The first slot, Slot 0, is reserved for the SharedDiagnostic Unit (SDU) while the remaining 16 slots canhouse up to 16 Model 3811 modems, or for mixednetworks, a combination of Model 3811 modems andModel 3611 Data Service Units (DSUs). An SDU is acircuit card that provides SDCP and network managementinterfaces to modems and DSUs installed in the carrier.SDUs are only required if a single SDCP is used bymultiple COMSPHERE 3000 Series Carriers in a cabinetor if a network management system (NMS) is used.For more details on the COMSPHERE 3000 SeriesCarrier, refer to the COMSPHERE 3000 Series Carrier,Installation Manual.3
