Seagate Elite 23 ST423451N, Product Manual

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52 Elite 23 Product Manual, Rev. A
The drive device connector is a non-shielded 68-conductor connector consisting of two rows of 34 female pins
with adjacent pins .050 inch apart. The connector is keyed by means of its shape (see Figure 16).
[1] Closed-end type 50-pin connector used. Install terminator enable (TE) jumper plug.
[2] Open-end type (in-line application) connector used. Terminators disabled.
[3] Host need not be on the end of the daisy chain. Another device can be on the end with the terminator, the
host having no terminator.
[4] Total interface cable length must not exceed that specified in Section 9.6.3.1 (including host adapter/initia-
tor). The number of devices allowed depends on data transfer rate. See Table 11.
[5] SCSI ID7 has highest arbitration priority, ID0 has lowest for “N” models. For “W” models, priority is ID 7 to
ID 0, then ID 15 to ID 8. (ID 8 very lowest).
[6] Last drive on daisy chain.
[7] Open-end type 68-pin connector used. Terminators disabled. If end device, external terminator and
closed-end type 68-pin connector used. On “W” models, install terminator enable (TE) jumper plug. “N”
and “W” models do not use external terminators.
Figure 14. SCSI daisy-chain interface cabling
Host Adapter
PCB
Pin 1
(check your adapter
for Pin 1 location)
“N” Model
Drive
SCSI ID 1
[6] [6] [6]
SCSI ID 0
SCSI ID 7 [5]
2 through X SCSI devices[4]
“W” Model
Drive
“WD” Model
Drive
Terminator
Note:
Do not mix
“W” and “WD”
model drives
on the daisy chain.
[7] [7] [1]
[1]
[2]
[2]
[3]