User`s guide

FCAL LRC I/O Module
6
2 Insert the module in the bay and press fully home (Figure 1–9).
Note Removal Is achieved by pushing the latch to the right and pulling the module out.
1.8 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:
1.8.1 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
1–5.
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 , Table 2–1 for further information. Alternatively a device
may use a Soft Address such that its AL_PA is dynamically allocated during loop initialization. The Soft Address
mode is selected by setting the Port ID Range switch to 8.
Note If conflicting IDs are selected the FC-AL initialization process will use soft addressing to allocate AL_PAs, this
could make the identification of particular devices difficult.
Table 1–1 shows the hexadecimal AL_PA values selected with each range switch setting.
Figure 1–9 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
Loop Path Tx<<<<<<<<<<Rx