User guide

Galaxy 55 User Guide
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Note Removal is achieved by pushing the latch to the right and pulling the module out.
2.9 Select ID and AL_PA
The Select ID of each drive bay can be set to one of eight ranges. these settings are read by the disk drives on SEL_0
to SEL_6 lines. The low order 4 Bits are fixed according to the position of the drive in the enclosure. The following
table shows the relationship between the Bay Position and the Drive Select ID bits:
* Bays 1/3 and 4/3 provide SES communications and must be populated.
2.9.1 Selecting Alternate Select ID Ranges
A Range switch is located on the rear of the LRC I/O module
The Drive Select ID bits, and hence the Arbitrated Loop Physical Address (AL_PA) range, can be changed by
setting the Range switch as follows:
Important Although there is a range switch fitted to each module, only the switch located on the UPPER
module will be active. This is indicated by the LED on the rear of the LRC I/O module, see Figure
1–11.
Arbitrated Loop - Physical Address (AL_PA)
Within the FC-AL protocol each device on a loop is allocated a unique Physical Address (AL_PA). This is derived
from the Select ID set described above. Please refer to Appendix A , ”Arbitrated Loop Physical Address (AL_PA)
Figure 2–17 Installing a FCAL LRC I/O Module
Bay
1/1
Bay
1/2
Bay
1/3*
Bay
2/1
Bay
2/2
Bay
2/3
Bay
3/1
Bay
3/2
Bay
3/3
Bay
4/1
Bay
4/2
Bay
4/3*
Select ID Dh 9h 5h Ch 8h 4h Bh 7h 3h Ah 6h 2h
1x12
Loop
Tx<<<<<<<<<<Rx
Loop 1,
2x6 IO
Tx<<<<Rx
Loop 2,
2x6 IO
Tx<<<<Rx