Total Access 850 System Manual Section 2 Engineering Guidelines64203376L1-1B © 2004 ADTRAN, Inc. 33DIP-Switch SettingsThe Total Access 850 SDSL RCU uses DIP-switches to determine power-up start mode. Table 9 providesdetails for the DIP-switches.4. REVIEWING THE REAR PANEL DESIGNAll connections are made through terminals, jacks, and wire-wraps on the backplane. A removable rearcover provides access to the backplane, and an access panel that mounts to the rear cover allows access towire-wrap strips P1, P3, and P5, power terminal strip (P7), and clock termination switch (SW1) withoutremoving the main rear cover. Most CPE applications will not require removal of the rear cover.Figure 6 shows the Total Access 850 backplane, and Table 10 on page 34 gives the backplane connections.Figure 6. Total Access 850 Rear PanelTable 9. SDSL RCU DIP-Switch S1 OptionsSwitch Function DescriptionS1-1 Firmware Mode ON* (down) The unit powers up in the firmware update mode.This mode is not used for normal operation.OFF Disables the firmware update mode.S1-2 Factory Defaults ON* (down) The unit powers up with the factory defaultsloaded.* Denotes factory default settings.Before removing the rear cover, do the following:For systems using PSU (P/N 1175006L1) –Remove the 20 Hz fuse before exposing backplane or accessing channel unit.For systems using PSU (P/N 1175006L2) –Depress the Ring Enable pushbutton to isolate the ring voltage from theTotal Access 850.P7P6P5
