COMPONENT DESCRIPTIONS10-30 Edition One XC1000 ServiceTable 10-9. Alarm-Configuration Switch Settings at S2 on theDistribution Board.S2 Switch SettingsSwitch SingleCabinetDualCabinetDescription1 OFF OFF +5-Vdc redundant power supply for cabinet 12 OFF OFF +12-Vdc redundant power supply for cabinet 13 OFF OFF –48 Vdc telecom present for cabinet 14 ON ON –48 Vdc telecom redundant for cabinet 15 ON OFF +5-Vdc present for cabinet 26 ON OFF +5-Vdc redundant for cabinet 27 ON OFF +12-Vdc present for cabinet 2*8 ON OFF +12-Vdc redundant for cabinet 2*9 ON OFF –48 Vdc telecom present for cabinet 210 ON ON –48 Vdc telecom redundant for cabinet 2*Switches 7 and 8 should be set to OFF only if +12-Vdc power supplies are installed in cabinet 2. If the second cabinet does not have+12-Vdc power supplies, set these switches to ON.10.7 DRIVES AND DRIVE BACKPLANESEach disk drive is enclosed in its own drive module. Each drive modulealso contains an I/O adapter board that combines the drive’s data, control,and power signals into one connector. Using this connector, the modulesare plugged into the disk-drive backplanes. The disk backplanes areconnected to the main backplane; the connection provides a communicationpath between the file cards and the disk drives.10.7.1 Drive ModulesThe drive modules are located at the lower front of the XC1000 cabinet.Slots for the system-drive modules are numbered 0 and 1 on the first shelf(system-drive shelf). Slots used by the message-drive modules are num-bered M0 to M3 on the second shelf (first message-drive shelf) and M4 toM6 on the third shelf (second message-drive shelf).The XC1000 currently uses two system drives. Up to seven message drivescan be installed. Each disk drive is enclosed in a drive module. The diskdrives are either 51/ 4-inch, 380-MB Winchester drives, which contain 48hours of message space, or 51/ 4-inch, 760-MB Winchester drives, whichcontain 96 hours of message space. Each disk drive is shock-mounted tothe drive-module cover. Ribbon cables connect the power and the controland data buses to the I/O adapter board installed inside each drive module.The I/O adapter board is mounted directly on the module cover and plugsdirectly into the disk-drive backplane when the drive module is inserted inthe drive slot. The I/O adapter board provides circuitry for multiplexingdrive data and clock signals between the disk drives and the disk-drivebackplane.SECTION 10.6 – 10.7
