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页码 22
 
Installation
1-5
 
Installing the HSSI Module
 
Cabling the HSSI Module for Network Connection
 
A SCSI-type cable connects the HSSI Module DTE connector to a Data Service Unit (DSU). 
Table 1-1 describes the connectors. Table 1-2 describes the pin assignments. 
3Com recommends using minimum lengths of this cable, especially if you plan to use these 
serial lines at high speeds. The maximum cable length allowed is 50 feet.
To connect the HSSI module to the network, insert a SCSI type cable into the female connector 
in the rear of the HSSI module
 
Table 1-1.  Connectors
 
Connector
Description
Plug connector type
2 row, 50 pin, shielded tab connectors,
AMP plug part number 749111-4 or equivalent 
AMP shell part number 749193-2 or equivalent
Receptacle type
2 row, 50 pin, receptacle header with rails and latch blocks,
AMP part number 749075-5 or equivalent
 
Table 1-2.  HSSI Adapter Cable Pinouts
 
Signal Name
Mnemonic
Pin Number
 (+ side)
Pin Number
(- side)
Direction
Signal Ground
SG 
1
26
--
Receive Timing
RT 
2
27
in
DCE Available
CA 
3
28
in
Receive Data
RD
4
29
in
Loopback Request
LC
5
30
in
Send Timing
ST
6
31
in
Signal Ground
SG
7
32
--
DTE Available
TA
8
33
out
Terminal Timing
TT
9
34
out
Loopback Circuit A
LA
10
35
out
Send Data
SD
11
36
out
Loopback Circuit B
LB
12
37
out
Signal Ground
SG
13
38
--
5 ancillary to 
DCE
14 - 18
39 - 43
out
Signal Ground
SG
19
44
--
5 ancillary from 
DCE
20 -24
45 - 49
in
Signal Ground
SG
25
50
--