Data transfer through optical fibre

[premkumar9]

Hi,
I need to transfer data from one microcontroller based device to another one located at a far away place. Optical communication cable is there between the the two locations which is already being used for intranet connectivity. The customer says that he can spare a dedicated line of 20MbPS to me. My data will be of 9600 KBPS only. Can anybody give some light on how to do this.

 

[MrAl]

Hi,

The simplest way is probably to simply purchase a transmitter and receiver, it two transceivers. They will convert the electrical signal to optical signals and back again so you only have to worry about the electrical signals.
You'll also have to think about how they connect to the optical cable, which might vary a bit, but should be found in the manufacturer's data sheets.

If you only have to do 9600 bps though you may want to build up something yourself but because it is far away you might have to use a laser diode rather than an LED. That could get a little more complicated because of the driver.
There's also a chance you might need a repeater but if that's not possible then it would probably be better to buy something that already does the conversions.

 

[JimB]

The customer says that he can spare a dedicated line of 20MbPS to me.

Before deciding to buy or build something, first consider what the customer is actually offering.

The optical line is in use and presumably has some Tx/Rx "devices" on each end of the line.

Is your customer offering you an unused optical line? ie "here is a fibre, connect your stuff to this"
or
Is he offering an unused channel on the modem/multiplexer/black box thing which converts electrical signals (RS232/RS485/Ethernet) to light and sends them up and down the cable.

Until you know this for certain, all discussion is just wild conjecture.

JimB

 

[KeepItSimpleStupid]

Well, if it were a "dark fiber", it would probably not have a data link speed of 20MbPS.

Even so, there isn't enough information to even attempt the problem.

 

[kubeek]

It seems to me that OP is being offered a TCP/IP link with 20Mbit bandwidth, and he wants to run a 9600Bd serial line over that. If that is the case, you got a lot of choices, like a dedicated PC on both sides or some ethernet to serial converters.

 

[premkumar9]

Thank you gentlemen for all your replies. I understand that I need to give some more inputs .
Actually this is a project for a customer who already have optical communication system which they use for intranet. I am developing some microcontroller based devices for them which are going to be installed at different stations which are far away by more than 800 kilometers.

Could any of you kindly list down what are the additinal information I need to colloct from the customer so that you can help me to choose the system required for this purpose.

 

[misterT]

Could any of you kindly list down what are the additinal information I need to colloct from the customer so that you can help me to choose the system required for this purpose.

How much are they paying you for asking questions on internet? How much are you willing to pay me for the info you need?

 

[premkumar9]

How much are they paying you for asking questions on internet? How much are you willing to pay me for the info you need?

There are lot of information available in net and there are many people who share their knowledge. I was only trying to get information from those source. If you that don't belong to that category, then please ignore my question. It is not meant for you.

 

[misterT]

You asked questions that only your employer can answer. Why did they hire you if you do not know how to accomplish the task? If this was a hobby-project I would be happy to help, but this just pisses me off.

 

[misterT]

Ok.. maybe I was out of line. I'm sorry.

You said: "The customer says that he can spare a dedicated line of 20MbPS to me"

What kind of interface are they providing? If the customer does not provide good specs about the interface, you can't do anything. If you expect to get help from other people, you need to give the same specs you are given.

 

[JimB]

I agree with misterT.

This is what I was getting at in my earlier post.

You must first get the interface specification for the proposed connection to the customers line.
That info can only come from the customer - it is their line! They should know!

(Or maybe they don't have the faintest idea either. In which case, you are stuffed!).

JimB

 

[premkumar9]

Keeping these in mind, I will talk with the customer again and try to gather more information.

 

[MrAl]

Hi,

After reading a couple replies i didnt realize that this site became a "Pay per View" site <chuckle>

premkumar:
You could ask the people with the fiber cable or whatever it is, what kind of interface that is. That's the most important question. From reading your first post i assumed it was a raw, unterminated fiber cable but now i believe it could already have transceivers on both ends. Those transceivers will have certain specifications and that is what you have to find out. They may be made to use a certain protocol.

Also, as far as i know this is still a free ask-as-you-wish site .
Whether you can get an answer here though depends on who is willing to help and also if they understand your question and also have any knowledge in that area. You'll find a lot of people here that are willing to help and have a wide range of knowledge so the chances are good that you will get at least some kind of help here. Sometimes it takes a few back and forth posts to ramp out all of the information though so you'll have to be patient too.

 

[premkumar9]

Thank you MrAl. Definitely I got some useful information from you. You said it well.

 

[eTech]

Thank you MrAl. Definitely I got some useful information from you. You said it well.

Hi

If your customer is offering use of an existing fiber "site to site link" that is currently provider intranet service, somewhere at each end, that fiber eventually gets converted to Ethernet for connecting intranet network devices. You may want to look at purchasing an Ethernet interface for your device. Or maybe a serial to Ethernet converter.

eT

 

[premkumar9]

Thank you eTech, I will definitely discuss wth customer and collect more details which will help me to take a decision.

 

[KeepItSimpleStupid]

Where I hear fiber, I think "dark". Meaning, "dark fiber" is just that, but even that has specifications. When I see 20 Mb/s added to that, there has to be an interface already.

You said serial interface.

We, have very bad crystal balls. We dont know if say a PC is going to connect to your serial device or these "serial devices" of yours have to talk to each other. Serial, 9600 BPS could man RS232, TTL RS232, RS422, and RS485 just to name a few. So, you as the OP did not even specify what you have.

As an example: https://bit.ly/HnkTk9

 

[premkumar9]

It is TTL RS232

 

[KeepItSimpleStupid]

so, do your little boxes need to communicate with each other or does a PC have to communicate to your little box?

I did not look at the manual for this module http://wiznet.co.kr/sub_modules/en/product/Product_Detail.asp?cate1=5&cate2=8&cate3=0&pid=1200, but it may be a place to start.

 

[premkumar9]

so, do your little boxes need to communicate with each other or does a PC have to communicate to your little box?

I did not look at the manual for this module http://wiznet.co.kr/sub_modules/en/product/Product_Detail.asp?cate1=5&cate2=8&cate3=0&pid=1200, but it may be a place to start.

My little boxes has to communicate with each other