M7/M7L/M7LT Modular Satellite Modem MaintenanceM7/M7L/M7LT - Rev. 0.05 2-172.3.8.5. High Speed Serial Interface (HSSI)2.3.8.5.1. HSSI Data Interface Connector (J26)The High-Speed Serial Interface connector is a 50 pin SCSI-2 on the rear panel (Figure 2-13) of theoptional interface card.Figure 2-13 – HSSI Interface Rear PanelConnection between the Router and the modem’s HSSI interface connector is via a Cisco CAB-1HSSI cable or equivalent. This cable has the same 50 pin SCSI-2 type connector on both ends.Connect the cable and insure that the retaining clips are engaged on both ends. The standard HSSISCSI-2 type cable designed to connect between a DTE Device, like a router, and a DCE such as theM7 modem is a 25 pair cable with shield. This cable is connected as a 1 to 1 pin connection betweenthe two male cable connectors. That means that pin 1 on one end goes to pin 1 on the other, pin 2 to2, etc, through pin 50 to pin 50.2.3.8.5.2. HSSI Overhead Channel Connection (J25)On the HSSI interface, the connection to the overhead data is on an auxiliary connector located onthe rear panel, the 25-pin male “D” sub connector J25. The pin-out of this connector is determined byinterface board(s) installed in the modem and the selected multiplexer mode. The pin definitions aredefined in Table 2-17 through Table 2-20.
