There’s no doubt that in this age of information technology, Internet is becoming an important part of our daily life. As a member of the Internet users, we maybe very familiar with the modem. With the advent of FTTh program, a new term which is called “Fiber optic modem (FOM)” comes into our vision. In fact, this device is accurately called “Serial to Fiber Converter” according to its working principle and applications. So, how much do you know about this device and do you know how to choose the best one? This paper is written as a solution which will introduces the serial to fiber converter and gives you some tips on how to choose the best one.
Introduction of Serial To Fiber Converter
Serial to fiber converter, also called fiber optic modem, is a device which is used in fiber optic networks for sending and receiving data of interface protocol. Serial to fiber converter provides electrical to optical conversion of electronic communication and data signals for transmission using tactical fiber optic cable assemblies. This device simultaneously receives incoming optical signals and converts them back to the original electronic signal allowing for full duplex transmission. Together with the tactical fiber optic cables, it provides a rugged, secure, and easy deployable optical link. In addition, the serial to fiber converter is available in both single and multi-channel configurations.
Serial Communication Interface Types of Serial To Fiber Converter
Serial to fiber converter provides the functions of RS-232/485/422 serial to fiber optic link. The following content will explain these three serial communication interfaces.
RS-232, namely EIA-RS-232, is a standard for serial communication transmission of data which formally defines the signals connecting between a DTE (data terminal equipment) such as a computer terminal, and a DCE (data circuit-terminating equipment, originally defined as data communication equipment), such as a modem. The standard defines the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pinout of connectors. RS232 interface is arguably the most well known connector on a personal computer, mostly used as the interface to modems. However, RS-232 only allows for one transmitter and one receiver on each line. RS-232 also uses a Full-Duplex transmission method. Some RS-232 boards sold by National Instruments support baud rates up to 1 Mbit/s, but most devices are limited to 115.2 kbits/s.
RS-422, also called as TIA/EIA-422, is a serial communications standard that uses fewer signal lines when compared to RS-232. Differential signaling can transmit data at rates as high as 10 Mbit/s, or may be sent on cables as long as 1500 meters. Some systems directly interconnect using RS-422 signals, or RS-422 converters may be used to extend the range of RS-232 connections. The standard only defines signal levels, other properties of a serial interface, such as electrical connectors and pin wiring, are set by other standards. It provides a mechanism for transmitting data up to 10 Mbits/s. RS-422 sends each signal using two wires to increase the maximum baud rate and cable length. RS-422 is also specified for multi-drop applications where only one transmitter is connected to, and transmits on, a bus of up to 10 receivers.
RS-485, also known as ANSI/TIA/EIA-485, TIA/EIA-485, EIA-485 or TIA-485-A, is a superset of RS-422 and expands on the capabilities. This standard can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear, multi-drop configuration which smartly address the multi-drop limitation of RS-422. RS-485 allowes up to 32 devices to communicate through the same data line and offers data transmission speeds of 35 Mbit/s up to 10 m and 100 kbit/s at 1200 m. Any of the slave devices on an RS-485 bus can communicate with any other 32 slave devices without going through a master device. Since RS-422 is a subset of RS-485, all RS-422 devices may be controlled by RS-485. Both protocols have multidrop capability, but RS-485 allows up to 32 devices and RS-422 has a limit of 10.
Overview of comparison of the above three serial interface:
|Mode of Operation||Single-Ended||Differential||Differential|
|Total Number of Drivers and Receivers on One Line. One driver active at a time for RS-485 networks||1 Driver1 Receiver||1 Driver10 Receiver||32 Drivers32 Receivers|
|Maximum Cable Length||50 ft (2500 pF)||4000 ft||4000 ft|
|Maximum Data Rate (40 ft – 4000 ft for RS-422/RS-485)||160 kbits/s (can be up to 1Mbit/s)||10 Mbit/s||10 Mbit/s|
RS-232/RS-422/RS-485 interface optic fiber modem is the best choice to connect RTU to HOST or SCADA controllers via multi-mode optical fiber. The RS-485 fiber converter can extend serial transmission distance up to 2km (multi-mode fiber) or up to 20km (single-mode fiber). With resistant to the effects of lightning strikes, power surges and other electromagnetic interference, the RS-485 fiber optical modem provides a reliable data network.
RS-232/RS-422/RS-485 interface optic fiber modem incorporates a method for automatically detecting the serial signal baud rate by hardware (Auto Baud Rate Detection). This is an extremely convenient feature for the user. Even if device baud rate is changed, the signal will still be transmitted through the RS232/RS-422/RS-485 to fiber converter without any problem.
Fiber Optic Connector Types of The Serial To Fiber Converter
Except the serial interface, the other end of serial to fiber converter should be a optical interface. Fiber optic cables connect the device through the fiber optic connectors. These connectors are usually available in ST, FC or SC types.
The direct advantage of serial to fiber converter is that it allows users to replace existing coaxial cable communication links with lightweight fiber optic cable. While the advantages of using fiber optic cable is as follows. All of these advantages impact defense mobility and rapid deployment requirements.
- Lighter weight and smaller size for much quicker deployment
- Higher bandwidth for increased throughput
- Lower loss for long distance repeaterless communication up to 20 kilometers
- Better quality-safe from electromagnetic interference from any source
- More secure – no electromagnetic signature
- Less expensive
Tips On How To Choose The Best Serial To Fiber Converter
Serial to fiber converters are the ideal when working with large amounts of data. Fiber optics allow data to be transferred quickly and effciently. Available in singlemode or multimode models. It is important you choose the option that’s best for your needs. Choosing the best fiber-optic modem depends on a few factors, including availability, usability and cost.
- Not all Internet service providers offer a fiber-optic option, so the first step to choosing a fiber-optic modem is to make sure you actually need one.
- Consider your computer equipment and specific needs when researching the best fiber-optic modem for your home or office.
- Modem installation is typically a simple do-it-yourself operation, but it is a good idea to ask before purchasing any equipment just to be sure.
- It also is a good idea to shop around as much as possible to find providers offering specials with fiber-optic connections.
- Once you confirm the provider, you should ensure the information of the interfaces (eg. optical connector, serial interface etc.), parameters (eg. working wavelength, supported fiber types etc.) in order to guarantee that it is the best to fit for your application.
Fiberstore’s Solution Of Serial To Fiber Converter
Fiberstore‘s serial to fiber converter are available in various form factors depending upon the protocol selected, such as RS-232/RS-485/RS-422 to fiber converter. Our serial to fiber converter has a higher bandwidth and greater electromagnetic immunity than wire-based modems. Together with multimode or single-mode fiber, the device allows data to be transmitted and convert electrical signals to light. It provides transmission distance up to 2km (multimode) or up to 20km/40km/60km (single-mode). Get more information about this product, welcome to visit our website or contact us by E-mail firstname.lastname@example.org.
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