Product manual

Product Manual - Hawk 2 Family (Wide bus) SCSI-2 (Volume 1), Rev. A 61
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[1] Part of active terminator circuits. Termination is required when the drive is first or last in the daisychain.
Terminators and a place to plug them must be provided by the user, systems integrator or systems
designer.
[2] ANSI SCSI compatible circuits
[3] Total interface cable length should not exceed that specified in paragraph 11.6.2.2.1.
[4] Arrangements for connecting terminator power to the terminators must be made by the systems de-
signer. The ST12400WC drive cannot furnish terminator power because the 80 pin I/O connector has no
pins devoted to terminator power.
[5] Interface signals levels and logical sense at the drive I/O connector are defined as follows:
Logic Level Driver Output Receiver Input
Negated (0) >2.5 V: <5.25 V >2.0 V: <5.25 V
Asserted (1) <0.4 V: >0.0 V <0.8 V: >0.0 V
The difference in the voltages between input and output signals is due to the losses in the cable.
Figure 11.6.4-1a. Typical single ended transmitters and receivers
Transmitter
(or transceiver)
Line Driver
Flat
Cable
Pair
(3)
(2)
(4)
(1)
110
Ohm
(4)
(1)
110
Ohm
Receiver
Line Receiver
(2)
TP TP