USB 3.0 Cable lenghts and distance options¶
Many applications and especially in Machine Vision require long lengths of the cable to allow remote distances connection of the camera to the host PC.
With the wide variety of solutions that are now present on the market and more being added, it becomes increasingly important to understand the benefits and differences between them to make sure that the most reliable and cost-effective is chosen and used minimizing the complexity and footprint of overall system.
1. Passive cables¶
These cables are most common and used at the moment.
You can find them in wide selection of lengths or even colors.
While being the cheapest solution they are typically restricted in length - up to 10 meters.
Be careful in choosing passive cables over 5m, they can be less reliable.
The main reason in such limitation is that copper cable exhibits signal loss over longer distances.
Other conditions that influence the signal are for example material choice, cable design, vendor overall quality or connectors.
2. Active cables¶
When distance is longer you will need to consider active cables where silicon micro chips start to be embedded in the cable for maintenance of signal strength and quality.
This approach gives copper cables additional length which can run reliably up to 25 meters.
Such solution can still be cost effective - cost Medium.
Also it can be additionally combined with passive cable.
Some cables are available with an option of external power connection that provides supplementary power to the particular USB device.
After certain length however the embedding of mentioned silicon chips complicates design and manufacturing.
3. Fiber extenders¶
Above 30 meters you should look for fiber-based solutions which can provide a reach of up to 100 meters.
Fiber extenders have two transceivers that help to convert the optical signal into electrical and back.
These transceivers connect to each other with fiber cable instead of copper and transmit signal by the means of light not electrical signal.
This results in the fact that even though they can transmit optical signal there is no power provided.
That means an additional source of power is needed for transceiver module itself and also the camera.
Mostly a proprietary hub is integrated within the transceiver and thus by providing power to the hub, both transceiver and camera will be operational.
To understand the whole setup you can imagine a route from host through USB3 cable to Fiber extender which has first a Local extender that connects with Fiber cable to Remote extender followed by the next USB 3.0 cable leading to the camera itself.
Remote extender is the one that needs to be connected to external power source. All parts of the setup can be exchanged to customize the length appropriately.
Important to mention is also Active Optical Cable (AOC) that is smaller in overall size due to integration of local extender parts into the cable making it a proprietary cable with a possible proprietary connection.
4. Angled and screw options¶
With USB3 becoming the most popular vision standard many new features and options arise also from the accessories vendors.
XIMEA is always trying to support or implement as many variations as possible for the customers to choose from.
At the moment we added to the offer a selection of cables with Angled connectors.
These are ideal for applications with space constraints like in case of embedded solutions or tight enclosures.
Plus there is an ongoing testing of a variety of cables that have connectors with screws on both sides.
5. High Flex cables¶
This is a special type of cables that are especially useful in the case of applications requiring excessive bending and other physical stress like with Robotic arms and environments where flexibility condition or sturdiness is critical.
There is a minimal number of times such cables need to be bent and continue working.
5000000 is the low standard, but companies tend to strive for 10M mark.
If you need to connect multiple USB 3.0 cameras to single host USB 3.0 hubs come into equation.
Such hubs can also be used to increase the cable distance in a multi camera system, even though it is not the most cost efficient choice.
Hubs tend to be offered with their own short cable up to 1 m, which connects host to the hub.
In combination with longer cables this further extends the reach of hub from the host.
To secure the necessary power requirements XIMEA advises to select hubs with external power.