Fc Lasers; Fc Speed Auto-Detection; Sfp Transceivers - Rorke Data Galaxy A16F-R2422 Installation And Hardware Manual

Fc-4g to sata-ii raid subsystem redundant controller

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Galaxy A16F-R2422 Installation and Hardware Reference Manual

4.1.2 FC Lasers

Lasers can be hazardous and may cause permanent eye damage or

blindness, and therefore must be treated with respect and used with

caution. Never look at lasers without knowing whether they are on or off.

Wavelengths: The lasers on fiber optic cables emit either short wave (SW)

beams (770nm-860nm) or long wave (LW) (1270nm-1355nm) beams.

Cables using either of these wavelengths can be used.

Laser types: Two (2) types of laser devices can be used in FC cables:

Optical Fibre Control (OFC) and non-OFC lasers. The OFC lasers are high-

powered and can be used over long distances.

Safety features: Due to their high power output, OFC lasers usually come

with a safety mechanism that switches the laser off as soon as it is

unplugged. Non-OFC lasers are low power and do not come with these

safety features; however, they can still inflict damage.

Speed auto-detection is specified by the Fibre Channel standard. If a 2Gb/s

(or 1Gb/s) port is connected to a 4Gb/s port, it will negotiate down and run

at 2Gb/s(or 1Gb/s). If there are two 4Gb/s ports on both ends of the link, the

link will be run at 4Gb/s.

1. If the Fibre Channel cable being used is too long for your system, it

may end up running at 1Gb/s even with two (2) 4Gb/s ports.

2. If DIP Switch 5 or 6 on the back of the subsystem rear panel is

manually selected to a specific transfer speed, FC speed auto-

detection function will be disabled.

Once you have purchased your FC cables, it may be necessary to connect

them to SFP transceivers. These transceivers should typically have at least

4Gbps bi-directional data links, a laser transmitter (for fiber optic cables),

LC connector, and a metal enclosure to lower the EMI.

LC connectors are small form-factor, fiber-optic connectors based on a

1.25-mm ceramic ferrule with the familiar latching mechanism of the RJ-

45 modular plug and jack.

4-2

CAUTION!

NOTE:

Subsystem Connection and Operation

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