Falcon 24 Dual Fibre Installation and Hardware Reference Manual
4.1.2 FC Lasers
CAUTION!
Lasers can be hazardous and may cause permanent eye damage, and
therefore must be treated with respect and used with caution. Never look at
lasers without knowing that they are turned 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. Although non-OFC lasers are low power and do not come with
this safety feature, they can still inflict damage.
4.1.3 FC Speed Auto-negotiation
Speed auto-negotiation is specified by the Fibre Channel standard. If a
1Gbps port is connected to a 2Gbps port, the 2Gps port will negotiate down
and run at 1Gbps. If there are two 2Gbps ports on either end of the link, the
link will be run at 2Gb.
NOTE:
1.
Fibre Channel transmission speed is also determined by cable length
and other
factors.
Make sure your connection and device
configuration meet the requirements specified by your cabling
devices vendors.
2.
If DIP Switch 5 on the back of the subsystem rear panel is manually
selected to a specific transfer speed, the FC port auto-negotiation
function will be disabled.
4.1.4 SFP Transceivers
Once you have purchased your FC cables, it may be necessary to connect
them to SFP transceivers. These transceivers should typically have at least
2Gbps bi-directional data links, a laser transmitter (for fiber optic cables),
LC connector, and a metal enclosure to lower EMI.
4-2
FC Host Connection Prerequisites
