Section 2 Engineering Guidelines ATLAS 550 System Manual44 © 2004 ADTRAN, Inc. 61200305L2-1BNxT1 HSSI Option Module (P/N 1200346L1), 50-Pin SCSI-IIThe NxT1 HSSI Option Module uses a single 50-pin SCSI-II interface to combine up to eight T1s of data(four from the NxT1 HSSI Module T1 ports and four from other T1 ports installed in the system). Table 26gives the pinouts for the SCSI-II connector, and Table 28 on page 45 gives the pinouts for the RJ-48C (T1)connector.NxT1 HSSI/V.35 Option Module (P/N 1200346L2)V.35 is possible with the NxT1 HSSI Option Module with an appropriate adapter cable (ADTRANP/N 3125I081@A); however, some HSSI menu options will be unavailable in this mode (for details, seethe User Interface Guide section). Table 27 and Table 28 on page 45 give the pinouts for the V.35 andRJ-48C (T1) connectors, respectively.Table 26. HSSI (SCSI-II, 50-Pin) Connection PinoutPin #(+ side)Pin #(- side) Description Pin #(+ side)Pin #(- side) Description1 26 SG - Signal Ground 10 35 LA - Loopback Circuit A2 27 RT - Receive Timing 11 36 SD - Send Data3 28 CA - DCE Available 12 37 LB - Loopback Circuit B4 29 RD - Receive Data 13 38 SG - Signal Ground5 30 LC - Loopback Circuit C 14-18 39-43 Ancillary to DCE (Reserved)6 31 ST - Send Timing 19 44 SG - Signal Ground7 32 SG - Signal Ground 20-23 45-48 Ancillary to DTE (Reserved)8 33 TA - DTE Available 24 49 TM - Test Mode9 34 TT - Terminal Timing 25 50 SG - Signal GroundTable 27. HSSI/V.35 Connection PinoutPin#(+ side)Pin#(- side) Direction Description1 26 — HSSI SG - Signal Ground2 27 O HSSI RT - Receive Timing3 28 O HSSI CA - DCE Available4 29 O HSSI RD - Receive Data5 30 O HSSI LC - Loopback Circuit C6 31 O HSSI ST - Send Timing7 32 — HSSI SG - Signal Ground8 33 I HSSI TA - DTE Available9 34 I HSSI TT - Terminal Timing10 35 I HSSI LA - Loopback Circuit A
