Product manual

40 Product Manual - Hawk 2 Family (Wide bus) SCSI-2 (Volume 1), Rev. A
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10.2.1.2 Termination
The reference index signal (REFIND+) is terminated with a 2 K ohm resistor. Each drive has a termination
resistor located on the Main PCB. The terminator resistor is not removable and is always in the circuit.
10.2.1.3 Physical interface
The dimensions of the connectors (J1-auxiliary and J6) mounted on the drive PCB to interconnect the drives
is shown in Figure 10.2.1-2a. They are 12 pin, 6 jumper position gold header type connectors. Pins 6 and 10
are used for connecting the Reference Index signal from drive to drive, as shown in Figure 10.2.1-2a. Pin 6
is REFIND+ and Pin 10 is ground. Either J1-auxiliary or J6 may be used. On "WC" models REFIND+ is J6-6
and on J1-37.
Figure 10.2.1-2a. Configuration select header specification for J6. (Connector at front end of PCB)
Figure 10.2.1-2b. Configuration select header for J1-auxiliary. (Connector at rear of model
ST12400W/WD PCB)
[1] J1-auxiliary pins are on 0.0787 inch (2 mm) centers as shown in Figure 10.2.1-2a for J6.
10.3 Grounding
Signal ground (PCB) and HDA ground are connected together in the ST12400 wide drive and cannot be
separated by the user. The equipment in which the drive is mounted is connected directly to the HDA and
PCB with no electrically isolating shock mounts. If it is desired for the system chassis to not be connected to
the HDA/PCB ground, the systems integrator or user must provide a nonconductive (electrically isolating)
method of mounting the drive in the host equipment.
.485 max
.020 +/- .001
(square)
.157
+/- .010
.394 +/- .010
.0787
(2mm)
typ
.048 min
.033 +/- .004
.0787 (2mm) typ [1]
.157
+/- .010
.236 max
.090
-.128
[1]
J1-DC Power
SCSI I/O Connector J1
Position 1A [1]
Position 1PPosition 1
J1-Auxiliary
REFIND+
1P2P3P4P
GND