Chapter 1. Introduction1-4 ESU LT User Manual 61200410L1-1Network Interface (NI)The Network Interface (NI) port provides the connection tothe E1. This port complies with the applicable ANSI andCCITT standards. Either the 120Ω DB15 or the 75Ω BNCinterface (adapter provided) may be used for the NetworkInterface. The 75/120 selection must be made with the frontpanel menus. For more information, see Wiring on page C-1.Network Test InterfaceThe MON test jack provides a bridges access jack for non-intrusive monitoring of the incoming E1.Nx56/64 Serial InterfaceThe Nx56/64 provides a serial interface that operates from56kbps to 2.048 Mbps. The Nx56/64 can be configured as aV.35,V.36, EIA-530, or V.11 electrical interface through thefront panel menus.Control Port InputThe control port input provides an EIA 232 input from a PCor a modem for control of the ESU LT. You can also use it as achain input from another ESU LT or ESU 120e. For moreinformation, see Wiring on page C-1.Chain Port OutputThe chain port output provides an EIA-232 output to chaincontrol to other ESU LTs or ESU 120es. For more information,see Wiring on page C-1.Software ManagementFront PanelThe front panel provides complete and easy control of allitems that can be configured through menu-guided options.The front panel LCD also displays the status of operation andperformance reports for the unit. A complete discussion ofthe operation of the front panel is found in Chapter 3,Operation on page 3-1. The menu options are found inChapters 4 through 7.