Dc Cable And Connector; Physical Characteristics - Seagate ST11200N Product Manual

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11.6.1

DC cable and connector

The drive receives DC power through a 4 pin connector mounted at the rear of the main PCB (see Figure
11.6-1). 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
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 drive may be daisychained together or with other compatible SCSI devices using a common cable.
Both ends of the cable must be terminated. The drive implements single ended drivers and receivers that
allow a maximum cable length of six metres (19.6 feet) (primarily for connection within a cabinet). All signals
are common between all SCSI devices. The drive may be daisychained only with SCSI devices having the
same type drivers and receivers. Devices having single ended interface circuits cannot be on the same
daisychain with devices having differential interface circuit. A maximum of 8 SCSI devices (including the
Host) may be daisychained together. The SCSI Devices at both ends of the daisychain are to be terminated.
Intermediate SCSI devices shall not be terminated (see Figure 11.6.3-2). Remove the terminator resistor
packs, not the terminator power source selector jumper (Figure 10.1-1).
11.6.2.2 Cable requirements
11.6.2.2.1 Single ended I/O circuits
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 and 11.6.3-1c.
11.6.2.2.2 Differential I/O circuits
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 intercon-
nection 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
11.6.3-1a and 11.6.3-1c.
Product Manual - Hawk 1 Family SCSI-2 (Volume 1), Rev. D
Table 11.6.1-1. Mating connector parts
Connector
AMP 1-480424-0
Contacts (20-14 AWG)
AMP 60619-4 (Loose Piece)
AMP 61117-4 (Strip)