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Fiber Optic Questions |
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1. |
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What is fiber optics? |
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2. |
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What are the advantages of
fiber optic Systems? |
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3. |
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When do I need to use fiber
optic systems? |
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4. |
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What does a typical fiber
optic system consist of? |
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5. |
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What is the difference
between Single-Mode (SM) and Multi-Mode (MM)? |
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6. |
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What are the usable fiber
optic cables for CommFront products? |
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7. |
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What connector types do your products
come with? |
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8. |
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What is the wavelength
for your fiber optic products? |
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9. |
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How many cores of the
fiber optic cable do I need in order to connect your fiber optic
converters? |
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10. |
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What is the maximum
distance for RS232, RS485 and RS422? |
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11. |
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What is the maximum
distance for 10 or 100M Ethernet? |
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12. |
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What are the typical fiber
link distances for your products? |
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13. |
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Can I connect an RS232
device to one side and connect RS485 or RS422 devices to the other
side of the fiber link? |
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14. |
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Are
there any jumper or DIP switch settings for serial data types or
baud rates for your RS232/RS485/RS422 to Fiber Optic converter? |
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15. |
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Are there any jumper or
DIP switch settings for 10/100M or regular/uplink port for your
Ethernet to Fiber Optic converter? |
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16. |
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What are the supported
baud rates for your RS232/RS485/RS422 to Fiber Optic converter? |
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17. |
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How many nodes can I
connect to RS485 or RS422 loop? |
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1. |
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What is fiber optics? |
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In its simplest terms, fiber optics is a
medium for carrying information from one point to another in the
form of light. Unlike the copper wire mode of transmission, fiber
optics is not electrical in nature. |
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2: |
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What are the advantages
of fiber optic systems? |
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Fiber optic systems have the following
advantages over copper wire systems: |
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Speed: Fiber optic systems operate at
high speeds - up to gigabits. |
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Bandwidth: Fiber optic systems have
large carrying capacity because light sources are used for
transmission. |
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Distance: Signals can be transmitted
much farther without needing to be regenerated or strengthened. |
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Resistance: Fiber lines are inherently
resistant to EMI/RFI and transient surges; therefore, they are ideal
for data communications near heavy electrical equipment and other
electrical or radio interference. |
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3: |
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When do I need to use
fiber optic systems? |
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Fiber optic systems are used for
transmitting information over long distances. For example, RS-232
has a distance limitation of 16 ft (5m). Some projects require the
RS-232 data to be sent over long distances, if it is transmitted
within 4000 ft (1.2km), then you can probably use an RS-232 data
repeater (such as CommFront's
RPT-232-3). However, if the distance is over 4000 ft (1.2km),
then a fiber optic system is recommended. |
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4: |
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What does a typical
fiber optic system consist of? |
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A typical fiber optic system consists of
a transmitting device, which generates the light signal; an optical
fiber cable (one or two cores for transmitting and receiving), which
carries the light; and a receiver, which accepts the light signal
that is being transmitted. The fiber itself is passive and does not
contain any active, generative properties. For CommFront products,
the transmitting and receiving devices are built within the same
device. Sometimes we call it a Fiber Optic Converter or Fiber Optic
Transceiver. |
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5: |
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What is the difference
between Single-Mode (SM) and Multi-Mode (MM)? |
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Two basic types of fiber and many
different types of fiber optic cables are used today. The two types
of fiber are called Single-Mode (SM) and Multi-Mode (MM). SM fiber
is more expensive, but more efficient than MM fiber, SM fiber is
generally used in situations in which the distances to be covered
are greater. |
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SM fiber is a
single strand of glass fiber with a diameter of 8.3 to 10 microns
that has one mode of transmission. SM fiber comes with a
relatively narrow diameter; the small core and single light wave
virtually eliminate any distortion that could result from
overlapping light pulses, providing the least signal attenuation and
the highest transmission speeds of any fiber cable type. The typical
distances for SM fiber are 12.4 miles (20 km) to 62 miles (100 km). |
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Multi-Mode fiber is a multi-strand of
glass fiber with a diameter of 50 to 100 microns. Light waves are
dispersed into numerous paths or modes, causing signal distortion at
the receiving end for long distance cable runs. The typical distance
for MM fiber is 1.2 miles (2 km). |
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Note: Fiber optic converter and fiber
cable must be of the same type, e.g. SM fiber optic converter must
be used together with SM fiber cable, while MM fiber optic converter
must be used together with MM fiber cable. |
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6: |
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What are the usable
fiber optic cables for CommFront products? |
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Almost all Single-Mod and Multi-Mode
cables are supported for CommFront fiber optic converters: |
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- Single-Mode:
8.3/125, 8.7/125,
9/125, 10/125µm;
- Multi-Mode: 50/125, 62.5/125µm. |
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7: |
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What connector types do your products
come with? |
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CommFront fiber optic converters come
with the options of ST, SC and FC connectors. |
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ST: A keyed bayonet type similar to a
BNC connector; it can be inserted into and removed from a fiber
optic converter quickly and easily. |
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SC: A push on/pull off connector with
a plastic housing and a locking tab; it is one of the earliest and
most commonly used types. |
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FC: A connector with a threaded body
which was designed for use in high-vibration environments. It is
widely used with both single-mode and multi-mode fiber. |
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8: |
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What is the wavelength
for your fiber optic products? |
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The wavelength for CommFront's fiber
optic converters is 1310nm (nanometers). Wavelength and frequency
are related, 1310nm falls into the frequency range of infrared. The
reason for infrared range frequency is that the attenuation of the
fiber is much less there. |
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9: |
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How many cores of the
fiber optic cable do I need in order to connect your fiber optic
converters? |
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The CommFront's fiber optic converters
(FBR-Serial-2
and
FBR-Ethernet-2) work in pairs (point to point); two cores of the
fiber optic cable are required, one for transmitting and one for
receiving. |
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10: |
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What is the maximum
distance for RS232, RS485 and RS422? |
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The typical maximum distance for
RS232 is 50 feet (15 meters); for RS485 and RS422, it is about 4000
feet (1.2 km) by using twisted-pair copper-wire cables. |
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11: |
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What is the maximum
distance for 10 or 100M Ethernet? |
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The typical maximum distance for
10/100M Ethernet is about 328 feet (100 meters) by using CAT-5e
twisted pair cable. |
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12: |
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What are the typical
fiber link distances for your products? |
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Depending on the
fiber cable and the type of converter used, a Multi-Mode fiber optic
link can go up to 1.2 miles (2 km), while a Single-Mode fiber optic
link can go up to 24.8 miles (40 km). |
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13: |
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Can I connect an
RS232 device to one side and connect RS485 or RS422 devices to the
other side of the fiber link? |
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Yes. Standards can
be mixed and matched, so an RS232 device can be connected to one
side of the fiber link, and RS485/RS422 devices to the other; or
RS485 (2-wire) devices can be connected to one side of the fiber
link, and RS422 (4-wire) devices to the other, without using a
converter and isolator.
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14: |
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Are there any jumper or DIP switch settings for
serial data types or baud rates for your RS232/RS485/RS422 to Fiber
Optic converter? |
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No. There are no
jumper or DIP switch settings in the unit. Simply connect the serial
data into its respectively connectors and hook up the system. The
FBR-Serial-2 supports data rates up to 460kbps and features data
format auto-sensing and self-adjusting, and, therefore, no DIP
switches or jumpers are required. When working with RS485 signals,
the CommFront’s auto-turnaround feature eliminates the need for flow
control. |
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15: |
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Are there any
jumper or DIP switch settings for 10/100M or regular/uplink port for
your Ethernet to Fiber Optic converter? |
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No. There are no
jumper or DIP switch settings in the unit. The
FRB-Ethernet-2
is a plug and play unit featuring auto-negotiation for half or
full-duplex and 10 or 100Mbps data rates. It also supports MDI
(straight-through) and MDIX (crossover) cables, no DIP switches or
jumper settings are required. |
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16: |
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What are the
supported baud rates for your RS232/RS485/RS422 to Fiber Optic
converter? |
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The
FBR-Serial-2 supports data rates up to 460kbps. It features data
format auto-sensing and self-adjusting. No DIP switches or jumpers
are required. When working with RS-485 signals, the CommFront’s
auto-turnaround feature eliminates the need for flow control. |
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17: |
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How many nodes can I
connect to RS485 or RS422 loop? |
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Up to 128 RS485 or RS422 devices can be
connected to the RS485/RS422 loop. |
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