Dc Cable And Connector; Physical Characteristics; Table 11.6.1-1 Mating Connector Parts - Seagate ST32430W Product Manual

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11.6.1

DC cable and connector

For Hawk 2LP W/WD models, the drive receives DC power through a 4 pin connector (see Figure 11.6-1a and
11.6.3-1b for pin assignments) mounted at the rear of the main PCB. Recommended part numbers of the
mating connector are listed below, but equivalent parts may be used (see Table 11.6-1).
Type of Cable
14 AWG
For Hawk 2LP "WC" and "DC" models*, the DC power is routed with the SCSI bus signals through the 80 pin
I/O connector. See Tables 11.6.3-1b and 11.6.3-1d for power pin assignments.
11.6.2

Physical characteristics

This section defines the connectors, cables, signals, terminators and bus timing needed to implement SCSI.
11.6.2.1 Physical description
The drives may be daisy-chained together or with other compatible SCSI devices. "W" and "WD" models use
the same type cable. Both ends of the cable must be terminated. The "W" and "WC" model drives implement
single ended drivers and receivers. The "WD" and "DC" models drive implements differential drivers and
receivers. All signals are common between all SCSI devices. The drive may be daisy-chained only with SCSI
devices having the same type drivers and receivers. Devices having single ended interface circuits cannot be
on the same daisy-chain with devices having differential interface circuit. A maximum of 16 SCSI devices
(including the Host) may be daisy-chained together. The SCSI Devices at both ends of the daisy-chain are to
be terminated. Intermediate SCSI devices shall not be terminated (see Figure 11.6.3-2). Remove the
terminator enable jumper TE on J2 select header ("W" models), or the external terminators ("WD" , "DC" and
"WC" models), not the terminator power source selector jumper TP (Figure 10.1-1).
"WC" and "DC" model drives plug into PCB or bulkhead connectors in the Host. They may be connected in a
daisy-chain by the host backplane wiring or PCB circuit runs that have adequate DC current carrying capacity
to support the number of drives plugged into the PCB or bulkhead connectors. A single 80 pin I/O connector
cannot support the DC current needs of several drives, so no daisy-chain cables beyond the bulkhead
connectors should be used. A single drive connected via a cable to a host 80 pin I/O connector is not
recommended.
11.6.2.2 Cable requirements ("W" and "WD" models only)
11.6.2.2.1 Single ended I/O circuits ("W" models)
The maximum total cable length for use with drives having single ended I/O driver and receiver circuits shall
be 6 metres (19.7 ft.) when operating at line data transfer rates of 5 Mbytes/sec or less, and 3 metres (9.85
ft.) when operating at transfer rates greater than 5 Mbytes/sec (FAST SCSI). A stub length of no more than
0.1 metre (0.33 ft.) is allowed off the mainline interconnection with any connected equipment. An ideal
impedance match with cable terminators implies a cable characteristic impedance of 132 ohms (see
11.6.2.2.3). Single ended I/O cable pin assignments are shown in Table 11.6.3-1a.
11.6.2.2.2 Differential I/O circuits ("WD" models)
The maximum total cable length for use with drives having differential I/O drivers and receiver circuits shall be
25 metres (82 ft.). A stub length of no more than 0.2 metre (0.66 ft.) is allowed off the mainline interconnection
with any connected equipment. An ideal impedance match with cable terminators implies a cable characteristic
impedance of 122 ohms (see 11.6.2.2.3). Differential I/O pin assignments are shown in Table 11.6.3-1b.
*The "DC" model designation has nothing to do with the type of power used. It designates an 80 pin, differential
I/O drive.
Product Manual - Hawk 2LP Family (Wide) SCSI-2 (Volume 1), Rev. A
Table 11.6.1-1. Mating connector parts
Connector
MP 1-480424-0
Contacts (20-14 AWG)
AMP 60619-4 (Loose Piece)
AMP 61117-4 (Strip)