Black Box Explains...Optical isolation and ground loops.
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Optical isolation protects your equipment from dangerous ground loops. A ground loop is a current across a conductor, created by a difference in potential between two grounded points, as in... more/see it nowequipment in two buildings connected by a run of RS-232 or other data line. When two devices are connected and their potentials are different, voltage flows from high to low by traveling through the data cable. If the voltage potential is large enough, your equipment wont be able to handle the excess voltage and one of your ports will be damaged.
Ground loops can also exist in industrial environments. They can be created when power is supplied to your equipment from different transformers or when someone simply turns equipment on and off. Ground loops can also occur when there is a nearby lightning strike. During an electrical storm, the ground at one location can be charged differently than the other location, causing a heavy current flow through the serial communication lines that damage components.
You cant test for ground loops. You dont know you have one until a vital component fails. Only prevention works. For data communication involving copper cable, optical isolation is key.
With optical isolation, electrical data is converted to an optical beam, then back to an electrical pulse. Because there is no electrical connection between the DTE and DCE sides, an optical isolator unlike a surge suppressorwill not pass large sustained power surges through to your equipment. Since data only passes through the optical isolator, your equipment is protected against ground loops and other power surges. collapse
Black Box Explains…Fiber Ethernet adapters vs. media converters.
When running fiber to the desktop, you have two choices for making the connection from the fiber to a PC: a fiber Ethernet adapter or a media converter like our... more/see it nowMicro Mini Media Converter.
Fiber Ethernet adapters:
Create no desktop clutter, but the PC must be opened.
Powered from the PC—require no separate power provision.
Require an open PCI or PCI-E slot in the PC.
Can create driver issues that must be resolved.
May be required in high-security installations that require a 100% fiber link to the desktop.
No need to open the PC but can create a cluttered look.
Powered from an AC outlet or a PC’s USB port.
Don’t require an open slot in the PC.
Plug-and-play installation—totally transparent to data, so there are no driver problems; install in seconds.
The short copper link from media converter to PC may be a security vulnerability. collapse
Black Box Explains...Advantages of fiber optic line drivers.
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Fiber optic line drivers are much better for communications than copper-wire alternatives because they offer three main advantages: superior conductivity, freedom from interference, and security.
Superior conductivity for increased performance
The glass... more/see it nowcore of a fiber optic cable is an excellent signal conductor. With proper splices and terminations, fiber cable yields very low signal loss and can easily support data rates of 100 Mbps or more.
Immunity to electrical interference
Because fiber optic line drivers use a nonmetallic conductor, they dont pick up or emit electromagnetic or radio-frequency interference (EMI/RFI). Crosstalk (interference from an adjacent communication channel) is also eliminated, which increases transmission quality.
Signals transmitted via fiber optic line drivers arent susceptible to any form of external frequency-related interference. That makes fiber connections completely immune to damaging power surges, signal distortions from nearby lightning strikes, and high-voltage interference. Because fiber cable doesnt conduct electricity, it cant create electrical problems in your equipment.
Electronic eavesdropping requires the ability to intercept and monitor the electromagnetic frequencies of signals traveling over a copper data wire. Fiber optic line drivers use a light-based transmission medium, so theyre completely immune to electronic bugging. collapse
PCI Fiber Adapters, SC
Installation and User Guide (Jul-05)