Physical Characteristics Of The Fibre Channel Interface; Supported Topologies; Address Assignments - Tandberg Data LTO 1 Setup, Operator, And Service Manual

Physical Characteristics of the Fibre Channel Interface

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Supported Topologies

Address Assignments

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IBM Ultrium Internal Tape Drive
The Ultrium Tape Drive Model T200F attaches to Open Systems servers by using
short-wave, multimode fiber optic cables. All cables feature SC-duplex connectors
and are designated as 50/125 (50 refers to the diameter of the optical fiber and 125
refers to the diameter of the cable; both are measured in micrometers). All cables
are for field or plant installation, and are available in the following lengths:
v 0.5 m (1.6 ft)
v 13 m (43 ft)
v 25 m (82 ft)
v 61 m (200 ft)
v Custom-length fiber cable
You can order fiber cables for specific lengths (other than lengths with feature
codes) by using part number 54G3391. The maximum length is 500 m (1640 ft).
Cable length is measured from the drive's Fibre Channel port. To order a cable, see
"Appendix A. Tools and Supplies" on page 81.
The drive supports Two-node Arbitrated Loop and Two-node Switched Fabric Loop
topologies.
Two-node Arbitrated Loop
The drive supports the arbitrated loop topology, but only two nodes are supported
on a loop.
Two-node Switched Fabric Loop
Two or more Fibre Channel end points interconnect through a switch. These
switches must have loop-attachment capability. Two nodes are supported on each
fabric loop.
Each device on a Fibre Channel loop must have a Loop Identifier (LID) and a
corresponding Arbitrated Loop Physical Address (AL_PA) to communicate with other
devices in the topology. The AL_PA identifies the device on the loop. (LIDs and their
corresponding AL_PAs are listed in Table 3 on page 17 and Table 4 on page 18.)
You can set an AL_PA by using one of two methods known as soft addressing or
hard addressing.
Soft addressing allows the drive to dynamically arbitrate the AL_PA with other Fibre
Channel devices on the loop. Hard addressing allows you to choose the LID, which
determines the corresponding AL_PA. The higher the AL_PA, the lower the priority
of the device.
Generally, servers (initiators) require that devices use hard addressing; they do not
support soft addressing. When setting addresses, assign the lowest AL_PA (and
thus the highest priority) to the server; assign the highest AL_PA (and thus the
lowest priority) to the drive.
To set soft or hard addressing, you must place jumpers on designated pins in the
drive's LID/status connector (see ( 2 in Figure 3 on page 11). The pin configuration
for soft and hard addressing is defined in "Step 6. Set the Arbitrated Loop Physical
Address (Fibre Channel Drive Only)" on page 15.