Optic Fiber to Ethernet Converter Board for ROV


Starting today, we begin pre-order for a fiber media board specially designed for ROV use. This board is designed to be as space efficient as possible while drawing very little power. It is capable of transmitting gigabit speeds with one strand of fiber while drawing less than 1W! Due to its high efficiency, the board itself also remains cool even under load.

Check it out here! :slight_smile:


Definitely looks interesting - nice work @DeepWaterExploration team! :slight_smile:

A couple of questions that I’m interested in:

  1. There seems to be quite a bit of space between the components. Is the board so spread out to help reduce high frequency noise causing interference, or are there many components on the base that require that extra space?
  2. Circular DC power jacks are generally very robust, but they can also take up quite a bit of space where the cable is inserted, which means extra space needs to be designed in around the board by users. Is there intended to be a smaller powering header/screw terminal for use inside an enclosure, or is it just this version that will be available, with the same board used at both ends?
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I can’t see well in the pictures or your web page … what type of Fiber connection are you using? Is it an UPC or APC end face? I am going to assume APC.

You have that it is bi-directional. Is your system switching between transmit / receive for the single strand or is this actually a dual strand system?

Are you providing a pre-polished cable that goes along with this board? What about cleaning instructions etc.? Fiber is wonderful, but can go down hill in a heartbeat for a numerous issues.


The fiber board in our picture is using LC/UPC connection, however since the transceiver is removable, you can probably find ones with different connections that suit your need.

In the testing, we have it in bi-directional with a single strand. We are not providing the cable at this point although there are several manufacturers of fiber optic ROV tether that we can recommend! For cleaning, it will be mainly on the transceiver side so I would follow the manufacturers instruction for that :slight_smile: .

Can you name them here? I know that Delta ROV sells fiber optic tethers, but I’m not sure about anyone else. Sometime in the fairly near future I will need about 2,500 feet of tether.

  1. So this is our prototype board since this deals with high speed signals, we had to test for radiation and such to make sure its compliance. Our final board can be much smaller than it already is but even at it’s current size, its still smaller than the competition!

  2. We have plans of adding a standard 2.54 mm connector next to the circular jack so there are multiple ways of powering the board!

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This is the tether we currently use on our ROV system. We choose their thicker version for added durability.

Little confused about bi-directional in a single strand. So you have a LASER on each end injecting into a single strand?

I have an application where we are pumping sixteen different frequencies in one direction down a strand. For bi-directional communications we use two strands. I am really curious as to how you are doing it with a single mode strand and how the “transceivers” are switching between injecting a single with a LASER and then switching to a photo detector.

Another question … you are testing your board for “radiation”. Are you talking about RF emissions?

Ok, found an article on the Bi-directional stuff. Single Strand Fiber Solution – Is It Right for You? | FS Community

So you are using 1310 and 1550 in a WDM setup. You can do that since you are only dealing with two frequencies that normally run over WDM. We happen to be using all sixteen at once in each direction over two strands.

Since you are using a smaller LC/UPC format … life is going to get interesting for people connecting their cables on site. For an easier clean with a UPC format I would have went with a larger ST or anything else in 2.5mm size. the smaller 1.25mm are easier to screw up.

No matter what interface you have, I would HIGHLY suggest to anyone going the Fiber route to at least get the proper gear to inspect / clean your connectors before you hook them up. Nothing will screw up your polish faster than dirt at a size you will never see. Fiber Instrument Sales has some nice regular Optical glass scope that our field installation guys use all the time for both 2.5 and 1.25 ferrules.

Another thing, get a good optical grade cloth or sticklers to clean the ends with or get ready to re-terminate your tethers or buy a new Transceiver board! Granted the boards in this thread all cheap as all heck for a price but your tether could run you some serious cash.

Our shop builds and test many types of fiber cables included hybrids from hell. We use digital inspection scopes and interferometers for 3D end face analysis so we no how quick and easy it is for an end face to get dirty within minutes after you just cleaned the blasted thing.

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Bi directional in a single strand injects different frequencies of through the fiber that are within a specific range so they can do full duplex communication. I am not sure about different applications with your case but we were able to transmit gigabit with one strand using our system as long as the 2 transceivers are designed to send and receive different wavelength of light.

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New Fiber Board done! :slight_smile:

Size comparison with RPi.

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Cool - nice work!
Looks great, and good to have a size reference for anyone interested in installing one in their vehicle :slight_smile:

The mounting holes look quite large - is the idea to have some kind of insert to the desired bolt size, or is it expected to use M4 or something?

By the looks of things it’s possible those hole positions won’t line up with existing ones in our electronics tray (understandably your board may not be designed to specifically suit Blue Robotics equipment). Is there a particular reasoning behind the hole spacings, and/or some kind of intended mounting system, or is the idea that users will just provide/create their own mounts for where they want to install the board? :slight_smile:

Hi Joseph,

I noticed this fiber media board do not have ports(label as tether input) for tether cables(small cables), just like in Fathom-X Tether Interface Board. Is it possible to receive response from tether without plugging in the mentioned tether cables?


Hi @taibproceanic, welcome to the forum :slight_smile:

These boards are for use with fiber-optic cables, which transmit their signal as light through optical fibers, so they’re not compatible with the copper wire tethers that the Blue Robotics Fathom-X is intended to interface with.

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Didn’t see this earlier! The screws are M3 which are standard with the Tray. Unfortunately, we could not align the screw holes to the dimensions of the Blue Robotics Tray as the transceiver and other modules take up a good amount of space and must be positioned in a very specific location. We will be looking into other ways of mounting though :slight_smile:

We also made changes so that we are using smaller power connectors.

Here is a link to it for anyone interested!

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Fair enough - not everything can work out to be perfectly convenient.

Cool. If you end up designing some kind of 3D printable mount that interfaces with our electronics tray then we can add it to our Enclosure Accessories collection on printables :slight_smile:

This looks great and very convenient - thanks for sharing! :smiley:
Also, I love the purple PCB :slight_smile: