Datasheet

Installing High-Speed Serial Interface Cables

OL-3435-02

HSSI Interface Cable

Null Modem Cable

Figure 2 on page 3 shows the HSSI null modem cable CAB-HNUL(=) (Part Number 72-0727-xx).

Table 2 provides pinouts. The cable has a male DB-50 (SCSI) connector on each end. Refer to

“Connecting the HSSI Cable” on page 4 for connection instructions.

Figure 2 Null Modem Cable Connectors

Table 1 HSSI Interface Cable Pinouts

Signal Name + Side Pin No. – Side Pin No.

Direction

Router DSU

1. Router is + side (DTE). DSU is – side (DCE).

SG (signal ground) 1 26 —

RT (receive timing) 2 27 <—

CA (DCE available) 3 28 <—

RD (receive data reserved) 4 29 <—

LC (loopback circuit C) 5 30 <—

ST (send timing) 6 31 <—

SG (signal ground) 7 32 —

TA (DTE available) 8 33 —>

TT (terminal timing) 9 34 —>

LA (loopback circuit A) 10 35 —>

SD (send data) 11 36 —>

LB (loopback circuit B) 12 37 —

SG (signal ground) 13 38 —>

5 (ancillary to DCE) 14–18 39–43 —

SG (signal ground) 19 44 <—

5 (ancillary from DCE) 20–24 45–49 —

SG (signal ground) 25 50 —

Table 2 HSSI Null Modem Cable Pinouts

Signal Name From Pins Direction To Pins Signal Name

RT (receive timing) 2, 27 —> 9, 34 TT (terminal timing)

CA (DCE available) 3, 28 —> 8, 33 TA (DTE available)

H5692