This all
translates into longer wiring runs along with the capability of sending
a larger volume of information longer distances safely. These are among
the advantages of fiber optic cable, and although copper cable has
proven to be adequate for security applications in the past, these
advantages may be strong enough to motivate an upgrade to fiber.
Fiber
optics emerged on the scene in the late 1950s and early 1960s, and was
adopted by the U.S. government and military at the height of the Cold
War. Happily, today’s costs of fiber are no longer as prohibitive as
they were in the late 1950s, and the cost for fiber optic cable is now
comparable to that of copper cable. Additionally, modern plug-and-play
design facilitates ease of installation.
Fiber optic media
converters are offered for a wide variety of signal types, enabling
security dealers and systems integrators to extend and protect their
customers’ data quickly and easily.
WHAT DOES IT DO?
In simple terms, a media converter takes a copper signal in, converts that copper signal to light, and transmits the light signal over fiber optic cable. A corresponding media converter positioned on the other end of the fiber optic cable then converts the light signal back to a copper signal.
For example, if an Ethernet signal is taken in and converted, an Ethernet signal is what is realized at the other end of the link. The same holds true for data communication signals such as RS-232, RS-485, or RS-422 as well as CCTV signals. Media converters generally work in pairs — one converter is placed at each end of a fiber optic link.
BENEFITS OF MEDIA CONVERTERS
Media converters offer several benefits to consider when designing security applications.
Increased signal distance — The distance capability of standard copper devices, such as those utilizing twisted pair or coaxial cable, are generally measured in feet and are limited. Fiber optic media converters can transmit data signals up to 110 kilometers depending on the devices and the type of fiber optic cable being used.
Data multiplexing — Because fiber optic cable offers greater bandwidth, media converters allow several data signals to be multiplexed and transmitted over one fiber link.
EMI/RFI suppression — The use of fiber optic cable and media converters will eliminate outside noise or interference from penetrating into copper-based equipment.
Grounding/lightning protection — Media converters provide isolation from grounding loops, transient voltages and lightning strikes that could damage equipment.
A range of media converters and switches can be used for video surveillance, access control, data and telephone communication, and networking applications.
VIDEO SURVEILLANCE
Video surveillance should not be interrupted due to lightning or other unexpected interference. A variety of media converter solutions for analog CCTV or IP-based security cameras are available.
Depending on the camera installation, media converters can be used in a point-to-point configuration or to multiplex several camera signals together for transmission over a single fiber link.
For analog CCTV cameras, media converters are offered with a variety of options, such as return pan/tilt/zoom (PTZ) data, bidirectional data and forward or bidirectional audio capabilities as well as contact-closure.
For IP-based cameras, media converters can be used in a point-to-point configuration, or a network switch with fiber optic capability can be used to multiplex several camera signals in order to put them on the network.
Additionally, media converters and switches are available with PoE (power over Ethernet) to provide IP-based cameras with power. This can be beneficial for remote cameras where access to power is limited.
ACCESS CONTROL
Access control in the form of card readers, keypads, intercoms and contact-closure signals requires extremely high signal reliability. An example of this is a perimeter entry gate installation.
Let’s say that you have a CCTV camera at the gate, a bi-directional intercom system, and a contact-closure on the gate itself, and all of these signals need to communicate between the gate and a main house or office that are several thousand feet apart. In the past, you would need to run wire and cable for all three signals and probably provide signal amplification in order to transmit over such a long distance.
However, with a fiber optic media converter, all these signals can be multiplexed on one fiber optic link and transmitted the full distance. This solution allows less cable to be run and less equipment to be installed, which reduces potential points of failure in the application.
DATA AND TELEPHONE COMMUNICATION
Media converters are available for data protocols such as RS-232, RS-485 and RS-422, as well as for telephone lines. The data media converters may be used when communicating between remote security devices and the control panel, or when communicating between a master control panel and a remote secondary control panel. The telephone media converters are perfect for intercoms and point-to point telephone ring-down circuits.NETWORKING
Networking applications probably are what most security dealers and systems integrators think of when the term “media converters” is mentioned. These are ideal for connecting networking equipment within a large building or in a campus environment. Devices are available that support Ethernet, fast Ethernet, and gigabit speeds.
Fiber optic switches are another type of media converter that have their own unique skill set. These devices are able to monitor the traffic passing through them and direct that traffic to the appropriate destination or block it from restricted destinations.
This monitoring capability allows the switch to control the traffic flow and avoid data collisions, thus increasing the efficiency of the network. Whereas a media converter is a point-to-point device, a switch can be used as a multiplexer and process multiple signals.
Today, Ethernet or IP-based networks are used for much more than just computers communicating with data servers or surfing the Internet. They are utilized to control HVAC systems, lighting, telephones, and yes, security. Media converters and network switches with fiber optic capability can be installed in any security application where copper wire normally would be used.
Media converter products are evolving at a rapid pace to provide a wide variety of solutions for security requirements. Security dealers and systems integrators who are looking for more secure communication and installation flexibility should give strong consideration to implementing fiber optic media converters into their future applications.
