OTDR Basis

by Fiber-MART.COM

With the development of technology, more and more fiber tools are available. They are used for testing at different stages of the network to meet various test requirements. These tests are used to reveal the total loss, optical return loss and fiber length, and the tests can be in a complete network or in a single fiber. Besides, the test may require further examination of the different elements of the measured link. Whether find fault in the network, or identify the characteristics of each component in the link, or locate potential problems for a fiber, all these will need to use optical time domain reflectometer (OTDR). OTDR is the ideal choice from commissioning to the optical network troubleshooting and maintenance.

 

OTDR is an optoelectronic instrument used to characterize an optical fiber. An OTDR is the optical equivalent of an electronic time domain reflectometer. It injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered (Rayleigh backscatter) or reflected back from points along the fiber. The scattered or reflected light that is gathered back is used to characterize the optical fiber. This is equivalent to the way that an electronic time-domain reflectometer measures reflections caused by changes in the impedance of the cable under test. The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of fiber length.

 

During the process of OTDR testing, the instrument inject a higher power laser or fiber optic light source pulse into a fiber from one end of the fiber cable at the OTDR port to receive the return information. When the optical pulse is transmitted through the fiber, there will be a scattered reflection. Part of the scattering and reflection will return to the OTDR. Useful information returned will be measured by he OTDR detector, and act as the time or curve segments of fibers at different positions. By recording the time used of the signals from transmission to returning, the transmission speed of the light in the glass fibers, the distance can be calculated.

 

The major advantage of the OTDR is that tests can be done from one end of the link and you do not have to access to the other end. This means that you don’t need two people to do the test and then save the problems of coordinating between people. Besides, it is much quicker for the testing. So even simple tests which could be performed with a basic optical source at one end of the link and a power meter at the other are often performed with an OTDR.

 

Many modern OTDRs come with additional functions such as optical power meter or laser source so that a good OTDR often has all of the function needed by a technician in the field. Moreover, many OTDRs offer computer output so that you can collect OTDR data in the form of digital readings and analyze it later on a computer. FS.COM has many kinds of OTDRs at reasonable price. If you are looking for an OTDR, FS.COM is an excellent option.

Buy Compatible Cisco Transceivers for Your Network

by Fiber-MART.COM

Cisco, established in 1984, is an international reputable company providing internet solutions, equipment and software products. It is also specialized in producing transceiver modules. Transceiver modules are widely applied to wireless communication devices. Deploying a Cisco transceiver module for your network is a best option for Gigabit Ethernet connection or fibre channel. Cisco transceivers have many advantages.

 

First, Cisco transceivers are of good scalability. Scalability means the inherent or potential capacity to rise beyond eight channels on one stand, which makes organizing and managing a network more easier.

 

Second, it is more simple and easy for Cisco transceivers to make the configuration. Configuration is able to lead the resources being depleted when an excess amount of time is taken in carrying out the process. The resources here can be in the form of a professional at work or any other monetary expenses as well. So using a Cisco transceiver can help to save your resources and cost. It brings benefit to you eventually.

 

Third, Cisco transceivers are considered to be the most reliable and capable forms of pluggable modules available and they are very suitable for large offices and organizations. We are living in a world full of various technology. Everyone needs to ensure that they are in control and connected. So having a system in place is essential and efficient. Cisco has the parts and system you require, and also it has excellent technical support. Thus choosing Cisco transceivers with a professional support team can help your network to back up and run quickly.

 

Fourth, a large selection of Cisco transceivers for different applications could be chosen. For instance, Cisco 100 Gigabit modules, Cisco 40 Gigabit modules, Cisco 10 Gigabit modules, Cisco CWDM/DWDM transceiver modules all can ensure the same prominent performance. You can choose the suitable one for your network.

 

Fifth, it is available for you to rent the transceivers from Cisco, which allows you to have a full technical support package. So it is a good choice to utilize Cisco transceivers for your Ethernet solutions, moreover, Cisco Transceivers are able to be used in conjunction with other pieces of equipment.

 

From above description, we could confirm that Cisco transceivers are so excellent, but original Cisco transceivers are very expensive. Buying compatible Cisco transceivers from other manufacturers would be a good choice, such as Fiberstore. Fiberstore has various cost-effective standards-based compatible Cisco transceivers, such as GLC-LH-SMD, SFP-GE-S, GLC-FE-100LX, etc. Buy a compatible Cisco transceiver for your network and then improve your network performance.

40G QSFP+ Optical Modules

by Fiber-MART.COM

As we know, fiber optical transceiver is an electronic device that receives an electrical signal, converts it into a light signal, and launches the signal into a fiber. It also receives the light signal, from another transceiver, and converts it into an electrical signal. Optical transceivers are becoming smaller, but more powerful, which makes them an important piece in server technology. It is the key component in fiber optic transmission. The basic interface of 40G QSFP+ transceiver modules are 40GBASE-LR4 and 40GBASE-SR4 in QSFP+ form factor.

 

40G QSFP+ Transceiver

40GBASE-LR4 QSFP+: 40GBASE-LR4 transceiver support with a link length up to 10 kilometers over 1310 nm single mode fiber, LC Connector. It is most commonly deployed between data-center or IXP sites with single mode fiber.

 

40GBASE-SR4 QSFP+: 40GBASE-SR4 transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. It can support the transmission distance up to 100 m with OM3 fiber and 150 m with OM4 fiber. The optical interface of 40GBASE-SR4 QSFP+ is MPO/MTP.

 

40GBASE-LR4 PSM QSFP+: 40G LR4 Parallel Single Mode (PSM) transceivers which are used to provide support for up to four 10Gbps Ethernet connections on a QSFP+ port over single mode fiber at distances up to 10 km.

 

40GBASE Extended SR4 QSFP+: Designed with optimized VCSEL with better performance of RMS spectral width compared with QSFP+ SR4. QSFP+ extended SR4 transceivers can support transmission distance up to 300 m with OM3 fiber and 400 m with OM4.

SFP+ compatibility issues? Here are 5 troubleshooting tips!

by Fiber-MART.COM

Have you ever tried to plug an optic SFP+ transceiver into an SFP+ port to discover that the connection didn’t work, i.e. traffic was very slow or there was no data transmission at all? Did you manage to diagnose the problem and find a resolution? There are several possible reasons for failure. We’ve listed the five most common ones.

 

sfp_plus

First of all, let’s briefly recap what SFP and SFP+ stand for. SFPs – short for ‘small form-factor pluggable’ – are compact, hot-pluggable devices that link networking devices, like switches, routers and servers. In this article, we focus on optic transceivers, as they’re called, which deliver 1Gbps of data across single-mode or multi-mode fibers. The SFP+ is an enhanced version of the SFP that supports data rates up to 10 Gbps. Now, the difference between SFP and SFP+ is an important one when troubleshooting: the transceivers are not always interchangeable.

 

TIP 1: Check whether you’re using SFP or SFP+ transceivers and slots

SFP and SFP+ modules look exactly the same. And as they have the same size, your SFP transceiver will fit seamlessly into an SFP+ switch port and vice versa. However, the connection won’t work as you expect it to. Or, worse even, it won’t work at all. If you plug an SFP device into an SFP+ port, the speed will be locked at 1 Gbps. Plugging an SFP+ module into an SFP port delivers no results at all, as the 10G transceiver can never auto-negotiate to 1Gbps.

 

TIP 2: Ensure that the SFPs have identical wavelengths at both ends 

Data transmission implies that data is sent from one end to another. The SFP+ transceiver on one end converts electrical signals into optical signals . A built-in laser transmits light through the fiber to the other side. Here, an optical diode converts the light back into an electrical signal. To guarantee that the SFP+ at the other end is capable of doing this, the SFPs at both ends should support the same wavelength. An 1310nm transceiver, for example, will not talk to an 850 nm transceiver.

 

sfp_flat

→ Here, too, look at the specs on the sticker of the modules or check out the details on the manufacturer’s website. Don’t look into the laser light ! Use your smartphone camera if you want to verify that light is coming out of the cable.

 

TIP 3: Use the correct single or multi-mode fiber cable 

Still in trouble even though you are sure you did not mix up SFP and SFP+ and are supporting the same wavelengths at both sides? If so, then verify if the optical transceivers on each end use the same fiber type, i.e. for single-mode or multi-mode fiber. And use the corresponding fiber cable.

 

Single-Mode Fiber (SMF): featuring a narrow core (typically around 9μm), SMF allows only a single mode (or “ray”) of light to propagate. It is mostly used to transmit data over long distances (max 2km – 120km).

Multi-Mode Fiber (MMF): as MMF has a much wider core (typically 50μm or 62.5μm), it allows multiple modes of light to propagate. The common MMFs are used for short distance transmissions (max 100m – 500m)

The type of fiber can be identified by use of standardized colors on the outer jacket:

 

fiber_type

TIP 4: Are both ports compatible with your SFP+ modules?

Even when using compatible SFP+s at both ends of the right cable, it is key that both of your devices support SFP+. Make sure that the SFP+ ports on your devices are compatible with the SFP+ modules you want to use. Some brands allow you to use only their own modules.

 

TIP 5: Is your optic cable in good shape?

Fiber optic cables are exceptionally vulnerable. Dust, dirt or tampering might cause physical damage. So, if you’re experiencing problems when connecting devices, check the connector, the module, and the module slot to make sure they’re not damaged.

 

To avoid physical damage, avoid extreme bends in fiber optic cables when storing them and put dust-caps on your cable ends if you disconnect them.

 

In summary, make sure that you know what you are doing when plugging in SFP+ modules and fiber optic cables! It may look simple, but transceivers and slots are not always compatible. Always check the specs on the sticker of your transceiver/the slot, or verify the details on the manufacturer’s website. Only when done right, using fiber optic cables that are in good shape, will you be able to transmit data at the desired speed!

 

Is the Optical Communications Market Growth for Real?

by Fiber-MART.COM

Reflection

The optical communications market is expanding as evidenced by growth in vendors’ revenues and margins. Moreover, companies are spending to increase manufacturing capacity and the outlook for growth is good. But some question the sustainability of this expansion.

 

The optical community has many participants who experienced the dot-com bust at the turn of the millennium and know firsthand the pain of over-extension.  My perspective is also shaped by that historical event. While my work today involves converting ideas to actionable plans, I was a market researcher at a well-known analyst firm before this role. I spent years defending the forecast of our market research firm, explaining how we missed that down-turn and what we had done to improve our forecasting process so it wouldn’t happen again.

 

Forecasting today’s market is just as challenging as it was in 2001. We are trying to estimate market performance that appears to have an insatiable demand for bandwidth with imperfect information and limited end-user resources to pay for the hardware.

 

Understanding the story behind the market performance and the forecast is among the most valuable lessons I learned. What’s the story behind this market?

 

The Market Is Up

Indeed the market is up and fiber and transceiver vendors have announced plans to increase capacity. Corning, an optical fiber and cable leader reports that market demand is exceeding supply. It plans to spend $176 million over the next two years to build a new optical fiber cable manufacturing facility and expand an existing facility.

 

Finisar, a leading transceiver vendor, reported record revenues and is running near capacity for its 100Gbps, QSFP28 transceiver. And Finisar expects this situation to continue through 2017. Moreover, it is planning to build a new facility in China and is expanding its VCSEL facility in Allen Texas, albeit to increase support for non-telecom products.

 

These are but examples to illustrate the need for more fiber—bringing optical connectivity to more places and simultaneously the need for more bandwidth per end-point, i.e.—increasing the data transmitted per fiber. Meanwhile, several vendors in the optical communication ecosystem are posting record revenues and earnings and projecting generally positive outlooks.

 

But there are also the market naysayers who experienced the dot-com bust and are wondering how long this will last. Is the growth real or is this another bubble? They don’t want to find themselves holding the bag with massive factories, excessive capacity and inventory, and no business.

 

And there is my buddy, the CEO of an optical infrastructure company, who says there is a twenty year cycle for telecom so expect the next down-turn around 2020. Just in time for the new factories to come online.

 

The Story Behind the Numbers

What’s driving growth today is the wild race by Web 2.0 companies to build large-scale data centers and capture the cloud services market and consumers. They are spending to connect equipment inside the data centers and to connect data centers from distances spanning a few kilometers across a campus to thousands of kilometers and, even, over submarine networks. The biggest demand today is to connect switches inside the data center, driving optical suppliers to develop and deliver new high capacity solutions.

 

Indeed, Finisar’s QSFP28 is for such an application. Luxtera, who is also shipping a transceiver for this data center application, reported that it too is sold out.

 

Meanwhile, the telcos are also spending to expand their networks. FTTH is growing in North America and the huge deployments in China continue. The 5G battle, which will require fiber to support the wireless network, is just gearing up in North America.

 

This combined effect has a profound impact on the volume demand for fiber connectivity and high-bandwidth transceivers driving revenue growth of the optical communications industry.

 

Real Growth, but...

Is the optical communications market growth for real? I think the story behind the performance suggests a strong market. In 2001 the market infrastructure revenue came from ostensibly one source: telecom operators. The Web 2.0 companies have expanded this base and diversified market segments contributing to optical communications ,thereby strengthening the financial foundation of this market.

 

But more information would help to improve the story and help market participants plan better. For example, a clear understanding of the Web 2.0 companies’ bandwidth demand would help. New data centers are being built globally and old ones being retrofitted on schedules shorter than previous generations. Services and underlying architecture connecting equipment are different. Correlating build cycles and bandwidth for service demands would help improve understanding the market and its evolution.

What is DDM/DOM for Fiber Optic Transceiver?

by Fiber-MART.COM

Usually when we buy SFP transceivers, we will have options with its DDM functions, so what is DDM? Obviously a SFP with DDM is high-ender than one which without DDM functions. What the DDM use for?

 

 

What’s DDM/DDM?

 

DDM is Digital-diagnostic-monitoring (this feature is also known as digital optical monitoring (DOM)) which provides a user with critical information concerning the status of the transmitted and received signals. This approach allows for better fault isolation and error detection.

 

 

Digital diagnostics monitor the SFP module’s temperature, receiver power, transmitter bias current, and transmitter power. Usually, the output of the physical value of each parameter is an analog voltage or current from the Trans impedance amplifier, the laser driver, or the post amplifier. Engineers use ADCs to digitize those physical values. With the digitized value, a microcontroller can then either process data as part of a control loop, trigger an alarm, or just record the data into a register.

 

 

The features of Digital Diagnostic Monitoring:

 

1. Monitoring module operating temperature

 

2. Monitoring module operating voltage

 

3. Monitoring module operating current 

 

4. Display module factory version.

 

 

 

Through real-time monitoring the module internal operating voltage and temperature, allowing the system administrators to find out some potential problems :

 

 

1) If Vcc voltage is too high, it will breakdown CMOS device; If Vcc voltage is too low, the laser does not work.

 

2) If received power is too high, it will damage the receiver module

 

3) If Working temperature is too high, it will accelerate the aging of the device.

 

What’s more, it can monitor the circuit and the performance of the remote transmitters by monitoring the received optical power meter.

 

 

 

Digital diagnostics monitor the SFP module’s temperature, receiver power, transmitter bias current, and transmitter power. Usually, the output of the physical value of each parameter is an analog voltage or current from the Trans impedance amplifier, the laser driver, or the post amplifier. Engineers use ADCs to digitize those physical values. With the digitized value, a microcontroller can then either process data as part of a control loop, trigger an alarm, or just record the data into a register.

FAQ about Gigabit Ethernet Transceiver Modules part 2

by Fiber-MART.COM

In the last paper we discuss the "FAQ we need to know about Gigabit Ethernet Transceiver Modules", and in this paper we are going to talk atout 10Gigabit Ethernet fiber optic transceiver.

 

Q:What are the main types of Transceiver Module?

 

A:Transceiver modules are available in various form factors, and can be optical (fibre optic) or designed for copper wiring. Different transceiver modules support different data rates, from 100Base (100 Mbit/s) up to 100GbE (100 Gbit/s). There are some common types of transceiver modules as the following:

 

 

Gigabit interface converter (GBIC) : 1 Gigabit EthernetTypes of Transceiver Module

 

XENPAK : 10 Gigabit Ethernet

 

X2 : 10 Gigabit Ethernet

 

Small form-factor plable (SFP) : 1 Gigabit Ethernet, also known as the Mini-GBIC

 

Small form-factor plable (SFP+) : 10 Gigabit Small Form Factor Plable

 

XFP : 10 Gigabit Small Form Factor Plable (slightly larger than the SFP+)

 

Quad Small Form-factor Plable Plus (QSFP+) : 40 Gigabit Ethernet

 

C Form-Factor Plable (CFP) : 40 – 100 Gigabit Ethernet

 

 

Q:What tools do I need when installing a Transceiver Module?

 

A:The following is a list of the tools which are recommended when installing a Transceiver module:

 

 

A Wrist strap or similar personal grounding device designed to stop ESD occurrences.

 

An Antistatic mat or similar which the transceiver can be placed on.

 

Fibre-optic end-face cleaning tools and inspection equipment.

 

A flat head screw driver is require to install a XENPAK transceiver module.

 

 

Q:What are CWDM and DWDM Transceiver Modules?

 

A:Wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e., colors) of laser light. WDM is divided into different wavelength patterns, conventional/coarse wavelength-division multiplexing (CWDM) and dense wavelength-division multiplexing (DWDM). In general, a CWDM (coarse WDM) MUX/DEMUX deals with small numbers of wavelengths, typically eight, but with large spans between wavelengths (spaced typically at around 20nm). A DWDM (dense WDM) MUX/DEMUX deals with narrower wavelength spans (as small as 0.8nm, 0.4nm or even 0.2nm), and can accommodate 40, 80, or even 160 wavelengths. CWDM and DWDM transceiver modules are the transceiver modules which are combined the CWDM or DWDM technology. The main advantage of both CWDM and DWDM is that they allow you to expand your networks capacity without the need for physical fibre optic cabling. Click and see 1GB DWDM transceiver price.

 

Q:What is DOM support?

 

A:DOM, short for Digital optical monitoring, is a feature which allows you to monitor many parameters of the transceiver module in real-time. DOM allows you to monitor the TX (transmit) and RX (receive) of the module, as well as input/output power, temperature, and voltage. Network administrators can then check and ensure that the module is functioning correctly.

 

Q:What is a ‘Red’ (RGD) Transceiver Module?

 

A:You may be interested in the “-RGD” in the product number of some transceiver module. In fact, these are enhanced transceiver modules which have been designed for greater durability, and can operate under more extreme conditions. Red transceivers may feature enhanced ESD protection, and extended operating temperature range.

 

Q:What are the main types of 10 Gigabit Ethernet SFP+ Modules?

 

A:10 Gigabit Ethernet is 10 times faster than gigabit Ethernet, with a data rate of 10 Gbit/s which is defined by the IEEE 802.3ae-2002 standard. The following list shows us fibre SFP module 10G types.

 

 

10GBASE-SR SFP

 

Medium: Multi-mode fibre (MMF)

 

Distance: up to 300 metres

 

Wavelength: 850 nm

 

10GBASE-LR SFP

 

Medium: Single-mode fibre (SMF)

 

Distance: up to 10 km

 

Wavelength: 1310 nm

 

10GBASE-LRM SFP

 

Medium: Multi-mode fibre (MMF)

 

Distance: up to 220 metres

 

Wavelength: 1310 nm

 

10GBASE-ER SFP

 

Medium: Single-mode fibre (SMF)

 

Distance: up to 40 km

 

Wavelength: 1550 nm

 

10GBASE-ZR SFP

 

Medium: Single-mode fibre (SMF)

 

Distance: up to 80 km

 

Wavelength: 1550 nm

 

10GBASE-LX4 SFP

 

Medium: Multi-mode fibre (MMF)

 

Distance: up to 300 metres

 

Medium: Single-mode fibre (SMF)

 

Distance: up to 10 km

 

Wavelength: 1300 nm

 

10GBASE-CX4 SFP

 

Medium: Copper

 

Distance: up to 15 metres

 

 

Q:How about fiber-mart Transceiver Modules?

 

A:fiber-mart provides a full set of comaptible fiber optic transceiver module solution cover all the famous brands, such as Cisco, HP, Finisar and so on, which can satisfy you with a full range of services. We guarantee the compatibility of all of our transceiver modules, and always ensure that they meet or surpass the standards set by the manufacturers of the devices in which they are intended for use.

 

Finisar, especially, you can find a full product line of our Cisco SFP with a good price and enjoy same-day shipping, such as GLC-FE-100LX, GLC-FE-100LX-RGD, GLC-LX-SM-RGD and Cisco compatible copper SFP, etc. According to your requirements, we welcome any inquiry for customized fiber optical transceiver. In addition, a variety of fiber patch cables are also offered with a good price and high quality. fiber-mart will give you a pefect solution for your network transmission.

How to Installing or Removing Transceiver Modules (Part I)

by Fiber-MART.COM

After learning more about a variety basic or conclusive knowledge of transceiver modules these days, I believe you must have a new understanding or a deeper perception on the transceiver modules. In fact, that's just a tip of iceberg. My blog will continue to bring more information about the fiber optic transceiver modules, such as SFP transceiver, SFP+ transceiver, XFP and so on. Also the other knowledge of fiber optic communication, network, telecom etc. to all of my friends who like this field and like my blog. Since we discuss so much about the theories of the transceiver modules, today, I prefer to talk about something practicle, for instance, some knowledge about installing or removing different kinds of transceiver modules.

 

As we know, the commonly used transceivers include the following 8 types:SFP Cisco

 

 

GBIC (Gigabit interface converter)

 

SFP (small form-factor plable)

 

SFP+

 

XENPAK

 

X2

 

XFP

 

QSFP/QSFP+ (Quad Small Form-factor Plable Plus (QSFP+) )

 

CFP (C Form-Factor Plable)

 

 

The following content will cover the knowledge of installing or removing for these types of transceiver modules, namely today's main topic. But first of all, I want to talk about some preparations and considerations before starting the main topic.

 

What equipment should we need to install a transceiver module?

 

When installing a transceiver module, some tools you should need in order to make your installation go well. The following is a list of such tools which are recommended:

 

 

 

A Wrist strap or similar personal grounding device designed to stop ESD occurrences.

 

An Antistatic mat or similar which the transceiver can be placed on.

 

Fibre-optic end-face cleaning tools and inspection equipment.

 

A flat head screw driver is require to install a XENPAK transceiver module.

 

 

What should we need to know before or during installing or removing a transceiver module?

 

In order to ensure the safety and avoid leading the unnecessary losses, there are some items which we should consider before and during installing and removing the transceiver modules.

 

 

To preventing the cables, connectors, and the optical interfaces from damage. We must disconnect all cables before removing or installing a transceiver module.

 

Please be aware that the regular removal and installation a transceiver module can shorten its useful life. Thus, transceivers should not be removed or inserted more often than is required.

 

Transceiver modules are sensitive to static, so always ensure that you use an ESD wrist strap or comparable grounding device during both installation and removal.

 

Do not remove the dust plug from the transceiver slot if you are not installing the transceiver at this time. Similarly, we must use the dust plug to protect the optical bore if we don’t use the transceivers.

 

 

How to Install or Remove Transceiver Modules

 

1. How to Install or Remove GBIC Transceiver Module

 

GBIC Installing Steps

 

 

step 1: Firstly you should attach your ESD preventive wrist strap to your wrist to prevent ESD occurrences.

 

step 2: Remove the GBIC transceiver from its protective packaging.

 

step 3: Verify that the GBIC transceiver module is the correct model for the intended network.

 

step 4: Using your thumb and forefinger, grip the sides of the GBIC transceiver and carefully align it with the GBIC socket opening on the device.

 

step 5: You can now carefully insert the GBIC transceiver module through the socket flap and slide it into the GBIC socket. A click will be heard once the GBIC is locked into the socket. Please ensure that the GBIC is inserted carefully straight into the socket.

 

(Please note: you should keep the protective dust plugs in place until making a connection. You should also inspect and clean the SC connector end faces immediately prior to making a connection.)

 

 

step 6: The dust plugs from the network interface cable SC connectors can now be removed, ensuring that these are saved for later use.

 

step 7: Next, inspect and clean the SC connector’s fiber optic end faces.

 

step 8: Remove the dust plugs from the optical bores on the GBIC transceiver module.

 

step 9: You can now attach the network interface cable SC connector to the GBIC.

 

GBIC Removing Steps

 

Please be aware that GBIC transceiver modules are static sensitive so you should always use an ESD wrist strap or similar grounding device when coming into contact with the device. Transceiver modules can also reach high temperatures so may be too hot to be removed with bare hands.

 

step 1: Disconnect the cable from the GBIC connector.

 

step 2: Release the GBIC from the slot by pressing the two plastic tabs located on either side of the GBIC (They must be pressed at the same time).

 

step 3: Once released carefully slide the GBIC straight out of its module slot.

 

step 4: The GBIC transceiver module should now be placed safely into an antistatic bag.

 

sing Fiber Optic Transceiver to Achieve Long Distance Transmission

by Fiber-MART.COM

Recently we met a big project that involved the network channel installation about digital optical transmission equipment, in fact, it is not so complex as the organization network ways, just we can use with SDH and downward access with switches over backbone line, but because of the SDH equipment covers all the site in the progress of construction, so it need to be solved for long distance network connections by another way. Fortunately, we have much experiences in using fiber optic transceiver, this page we will introduce the application of fiber optic transceiver in the network construction progress which combines with this experience.

 

1. Multimode fiber optic transceiver and multimode fiber optic cables

Fiber optic transceiver is an ethernet transmission device that can exchange the light signal and electrical signal, fiber optic cables that can transfer data over network can be divided into multimode fiber optic cables and single-mode fiber optic cables, fiber core diameter of multimode fiber cable is 50~62.5 Ľm and the single-mode fiber cable core diameter is 8.3 Ľm. In fact, these data are not intuitive for us, we can judge it only by colors, the multimode fiber pigtail's color is orange and the single-mode fiber cable is yellow. From the network applications, because of multimode fiber optic cable can transmit for not tool long distance, it just can be used between the buildings, but because of the price is relatively cheap, so there are still some people like to use it. HP J4858C SFP transceiver in figure 1.

 

Figure 1. HP J4858C SFP 850nm 550m Multimode Optical Transceiver

 

HP J4858C

 

2. Single-mode fiber optic transceiver series

With the development of technology, this phenomenon that single mode fiber cables applied into the long distance network installation is more and more popular, nowadays many customers use fiber optic transceiver directly, just we call it FTTH (fiber to the home), and these different types of fiber optic transceivers we will introduce to you all based on single mode fiber cables. HP transceiver JD119B Single-Mode SFP in figure 2.

 

Figure 2. HP JD119B X120 1310nm 10km Single-Mode Optical Transceiver

 

HP transceiver JD119B

 

Dual Fiber Single Network Port

The dual fiber single network port fiber optic transceiver just use two fibers, a fiber is used to receive and another is used to transmit. A group of fiber optic transceivers can achieve the exchange of electrical signal and light signal. The network device may a switch, also may a server, well, we can see the fiber optic transceiver as PC, which connected with the switch is straight through cable, and with the server is cross cable. With the development of technology, the fiber optic transceiver ports have been generally made adaptive mode (automatic matching cross-line and direct line), it also bring conveniences to the projects.

 

Single Fiber Single Network Port

With the continuous development of business, we are faced with an unavoidable problem that the shortage of fiber resources. Some companies want to connect the network but there is only a fiber, it is time to use the single mode fiber optic transceiver, it means that receive and transmit signal over a fiber, this product use WDM technology, related product: passive cwdm mux (shown as the figure). The wavelength usually are 1310nm and 1550 nm, and the 1310 nm stands for transmission, and the 1550 nm stands for receiving.

 

cwdm

 

Single Fiber Dual Ethernet Port

With the development of business, some units put forward higher requirements, for example, we organized network for one bank, he asked us to provide two Ethernet lines to separate from. it needs mature and safe fiber optic transceiver device technology, in order to simply the cost of fiber optic devices and achieve the networks over one fiber, we try our best to save the fiber sources. Our solution is that using 10/100 m adaptive port devices, access into the Ethernet link which can reach 60 km, also keep it to support network management functions.

 

3. Gigabit fiber optic transceivers and integrated optical interface switches

The advantages of using fiber optic transceiver to connect the network, not only stable, but also it has fast speed, 100M full duplex and even 1000M duplex. For example, there is a Engineering machinery manufacturing enterprise, they use the 100M link to network at the beginning, but due to the requirements of the developments of business, we need to provide higher speed to them, fortunately, the progress of the technology provide good products for us, just gigabit fiber cable, from the appearances of fiber cable, it has no differences with 100M fiber transceivers. Yeah, the fiber optic transceiver we used can be directly pled into the original power supply unit box, which just needs to change the fiber optic transceiver and then upgrade the bandwidth from Fast to Ethernet. Otherwise, we found that the education industry prefer to use an integrated gigabit fiber interface on the switches.

Design and Research of Intelligent SFP optical module

by Fiber-MART.COM

Introduction

 

In the optical communication products, optical module occupies has a very important position. Optical transceiver module as one of the key technologies of optical fiber communication network, is widely used in synchronous optical network SONET) and Synchronous Digital Hierarchy SDH), Asynchronous Transfer Mode (ATM), Fiber Distributed Data Interface (FDDI), as well as Fast Ethernet and thousands Gigabit Ethernet and other systems.

 

In the present optical communication products, fiber optic transceiver module has been more popular than others, SFP GBIC module module volume ratio reduced by half, but also supports hot-swap capabilities, has been widely used. Meanwhile, in the various existing networks needed optical transceiver module types, more and more requirements are also increasing. To meet the ever increasing performance requirements of the system,Optical module continues to develop intelligent, fast and high-density interconnect direction.

 

Intelligent SFP optical modules, namely USES the fiber optic sfp module of digital diagnosis function, will become a new generation of optical transceiver module integrated in the window.It can realize network management unit real-time monitoring the temperature of the transceiver module, power supply voltage, bias current, as well as the transmitting and receiving optical power.Through monitoring of these parameters, we can help system administrators predict the life of the light module, fault isolation system and authentication module in the installation of compatibility, etc.

 

A smart SFP optical module system design

 

1.1

 

Transmitting section

 

The main role of the light-emitting process in the optical transmission module is to convert the optical signal into an electrical pulse signal is a pulse, the electrical signal is input, the output optical signal. Transmitter module, mainly by the laser driving circuit and the TOSA. Which TOSA backlit by the laser diode LD and PD components. LD is used in vertical cavity surface emitting laser VCSEL.

 

First electrical modulation of the laser drive lasers to meet the input digital fiber optic communications system required drive signal, the drive signal from the bias current Ibias And the modulation current Imod composition, the laser emits an optical signal corresponding to the driving of the driving signal, the optical signal is coupled into the optical fiber and transmitted to the receiving end. In this scenario, the laser driver selection MAX3286.

 

Laser driver with the functions of automatic power control (APC), APC circuit using the backlight diode in the TOSA, monitoring laser the size of the backlight.When the optical power is less than one rating, through increase the drive current feedback circuit, laser output power increases as the rated power value.Conversely, if the optical power is greater than a certain rating, is through feedback circuit reduce drive current, laser power output is less.APC circuit can dynamically adjust the laser power, therefore, the size of the bias current, can automatically compensate laser due to the change of ambient temperature or aging caused by the change of the output optical power, keep the output optical power range is relatively stable.

 

 

Receiving part

 

The main role of the receiver module is attenuated after

 

deformation weak optical fiber cable transmission signal to a pulse electric pulse signal by photoelectric conversion, and give sufficient amplification, a standard reduction of the digital pulse signal. Optical receiver module schematic shown mainly by the photodiode PD, a preamplifier, a limiting amplifier and other components. Which photodiode and preamp integrated package together constitute ROSA.

 

A photodiode is a core device of a digital optical receiver, an optical pulse signal will be the electrical pulse signal by photoelectric conversion, commonly used are PIN photodiodes and avalanche photodiode APD. Optical signal from the optical interface enters the photodiode PD, is converted into a weak current, the current through the pre-amplifier and converted into a voltage level is amplified to an appropriate level.

 

Effect limiting amplifier output of the preamplifier is the magnitude of different amplitude analog signal into a digital signal, these signals can be amplified. To photoelectric detectors with a good match and get the low-noise and wide-band preamplifier gain is not too high, the preamplifier output voltage amplitude is usually from a few millivolts to tens of millivolts, such small signals can not be directly output optical module is therefore necessary to further enlarge the signal; the other hand, the photodetector detects the light signal from the amplitude of the current signal in a defined tolerance level, the tolerance limits of the capacity of the fiber considered Poor, splice loss and the parameter fluctuations caused by temperature and aging, however, the data for further processing, the signal amplitude is preferably a constant value.

 

Therefore, limiting amplifier requires a certain dynamic range, which usually requires a dynamic range of more than 20dB.

 

1.3

 

Digital Diagnostics DDM part

 

Digital diagnostics mainly composed of MCU to complete. By temperature MCU, the network management unit may receive real-time monitoring module, the power supply voltage, laser bias current and the light emitting and receiving power. By measuring these parameters, the management unit can quickly identify the specific location of fiber link failure occurs, simplify maintenance, improve system reliability.

 

Five DDM parameter acquisition circuit for acquisition by the first conversion, the inputs to the ADC, ADC five circuit analog voltage into a digital signal sent by the decoder circuit is stored in a memory support DDM corresponding address bit . Transmission of information via a two-wire serial interface (SCL clock line and data line SDA) to achieve.

The basic principle and function of multifunctional SFP digital diagnosis

by Fiber-MART.COM

In recent years, fiber optic communications network has achieved rapid development. Optical transceiver module as one of the key technologies of optical fiber communication network is widely used in a variety of optical communication systems. Smart SFP optical module, which uses digital diagnostic functions fiber optic sfp module, it can achieve real-time monitoring of network management unit transceiver module temperature, supply voltage, laser bias current, and optical power transmission and reception. The measurement of these parameters can help identify the location management unit fiber link failure occurs, simplify maintenance, improve system reliability. Optical modules to achieve real-time monitoring capabilities for effective life prediction module, isolation system failures, as well as to verify the correctness of the module status during the installation and commissioning of high practical value. The author based digital diagnostics, design and implement a monitoring platform of an optical module. The platform uses the microcontroller via a 2-wire serial bus to access the modules to read and deal with related parameters, while module parameters to be read in real time through the LCD display. And with CDR (clock data recovery) section, can signal clock recovery and data retiming, as a basis for hardware monitoring module in the relevant technical specifications designed monitoring platform.

 

1.1 the basic principle of digital diagnosis

 

In the SFF-8472MSA, the specification of the digital diagnostic functions and related SFF-8472 for details. The specification, in the northern part of the circuit board module detection and digital signal parameters. Then, provide calibrated results or provide digitized measurements and calibration parameters. This information is stored in standard memory results in order to read through the two-wire serial interface. Retained the originalbidi sfp transceiver / GBIC Address Address A0h at the map and added a 256-byte storage unit at the address A2h SFF-8472 in the agreement. This information is stored in addition to providing parameters to detect, but also defines the alarm flag or alarm conditions, the state of the mirror each pin, limited number of control and user-writable storage unit.

 

1.2 The role of digital diagnostics

 

(1)intelligent life prediction 10g sfp module provides a prediction methods of the parameters of the laser degradation of real-time monitoring.Light module within the light power feedback control unit will power output control at a stable level, power control is by increasing the laser Tx_Bias (offset current).Therefore, we can through the monitoring of the laser bias current can be used to predict the life of the laser.

 

(2) fault location In optical links, the location of the fault occurs is critical to business fast load positioning.Fault location, need comprehensive analysis of status, a pin and measuring parameters.Through to the detected Tx_power (sending power), Rx_power (received power), Temp (temperature), Vcc (voltage), Tx_Bias (offset current) warning and alarm status, Tx Fault image of the state variables (alarm) and RxLOS (receiving signal loss), and other information for comprehensive analysis, can locate the Fault is in the module or on the lines, in local module or in the remote module.

 

(3) compatibility verification by monitoring the voltage is outside the specified range, whether the received optical power overload or below the receiver sensitivity, temperature exceeds the operating temperature range, etc., work environment analysis module meets the data sheet or compatible with the relevant standard.