Seagate ST12400N Product Manual page 69

Product Manual - Hawk 2 Family SCSI-2 (Volume 1), Rev. B
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[1] Part of active terminator circuits. Permanently mounted LSI terminators enabled in the drive (ST12400N
only) when it is first or last in the daisy-chain. See jumper header Figure 10.1-1 for terminator enabling jumper
TE.
[2] ANSI SCSI compatible circuits
[3] Total interface cable length should not exceed that specified in paragraph 11.6.2.2.1.
[4] Source of drive terminator power is an active circuit which has an input source voltage selected by jumper
plug TP. See Figure 10.1-1. This applies to model ST12400N only.
[5] Interface signals levels and logical sense at the drive I/O connector are defined as follows:
Logic Level
Negated (0)
Asserted (1)
The difference in the voltages between input and output signals is due to the losses in the cable.
Figure 11.6.4-1. Single ended transmitters and receivers
Line Driver
TP
Transmitter
[4]
(or transceiver)
[1]
[2]
Driver Output
>2.5 V: <5.25 V
<0.4 V: >0.0 V
Line Receiver
TP
[4]
Flat
110 110
Cable
[1]
Ohm Ohm
Pair
[5]
[3]
Receiver Input
>2.0 V: <5.25 V
<0.8 V: >0.0 V
Receiver
[2]
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