Before you pay for a site visit, I would first try purchasing a mains-powered USB 3.0 hub and plugging your camera into that instead of having it plugged directly into your Dell. It instantly fixes camera problems for most people who do this if their PC meets RealSense's specifications (as your laptop's Kaby Lake type processor does), as RealSense cameras are very sensitive to the state of USB ports. You can get a hub for 15 to 20 euro from Amazon France by searching for 'powered usb 3.0 hub'.
A powered hub won't fix issues that are related to the device's specification being incompatible (e.g a processor that is too old or the wrong architecture). But usually with SR300 cameras, if a PC has a compatible processor, a USB 3.0 port and is running Windows 10 then a powered hub is a quick and easy fix.
Thanks for the answer.
You are totally right, the USB powered hub is an effective fix for my issue and a very good short term solution.
This is something that we can do to quick fix these instability issue but the problem is the amount of cables and the loss of mobility. Are clients are not geeks and I would like to give them a simple, clean device.
Since the USB powered hub works well, I am looking at our Dell Vostro 3568 USB 3.0 power. I noticed that it has SuperSpeed but i'm not sure anymore that it really has the complete power of an USB 3.0 port. Do you know if there is some way to identify the "real" and "fake" USB 3.0 ports? Changing to another PC is a serious option. Maybe upgrading to a professionnal model would solve our problems.
Upgrading to a professional model is not necessarily a solution for the USB problem. There are users with top-end Xeon enterprise workstations who have also had to use powered USB hubs to fix their camera issues. I have a budget Acer Aspire ES15 laptop with Skylake processor - the cheapest I could get with a Skylake in it so I could use modern RealSense cameras - and I can use the cameras without a powered hub. So expense does not guarantee camera success.
I would avoid mobile devices that are described as having 'USB OTG' 3.0 ports, which stands for On The Go. Whilst it has been shown to work with RealSense - the RealSense R200 Robotic Development Kit mini-board has one - you are safer going with a device that has a true full USB 3.0 port. Likewise, some mobile devices are reputed to save money by implementing a pair of USB ports as an unpowered hub instead of having two truly separate ports. RealSense does not like unpowered hubs.
There is a way to check if SuperSpeed is operating with a connected USB device. In the text box at the bottom of your Windows screen, beside the button where you shut down, type in 'settings' to find the Settings app. Open it and Select Devices and then Connected Devices.
If a connected USB 3.0 device is running at SuperSpeed then it says 'Connected to USB 3.0'. If it is running at less than SuperSpeed then the message instead says 'Device can perform faster when connected to USB 3.0'. Of course, there's no way to check a device is running as fast as it can until you have actually purchased the machine!
Even then, SuperSpeed may not be a useful guide. Even if the camera can run at full speed when connected to the PC, the problem occurs when the camera tries to draw more power from the USB port than the port can stably supply. The maximum power the port can supply is not something that the Settings window can predict.
I find that a good way to decide whether a particular device will be suitable for RealSense is from reports on the RealSense forums. If I see a certain model appear in messages more than others then I am not likely to consider purchasing that model for use with RealSense. For example, Microsoft Surface Pro and Surface Book portable devices have a history of problems with RealSense. So if you see a certain model you are considering, you could search for that model number on the RealSense forums and see if there are any reports of problems.
In some cases, a USB problem can also be remedied by changing to different USB driver software than that provided by the manufacturer.
Another way to tell if a particular model is likely to have USB problems is to search for whether people have had issues with using external hard drives with that computer, since high drain devices like external hard disk drives place a demand on the USB 3.0 port in the same way that the RealSense camera does. And it is easier to find such reports, as more people have external hard drives than RealSense cameras.
Looking further ahead into the future, your clients may be able to use the forthcoming wireless Project Alloy wireless headset (which has a full Kaby Lake PC inside the headset) to take the measurements, if it is not too geeky for them.
Thanks Marty for the tips!
The SuperSpeed USB is working well on the Dell Vostro 3568 (it is actually written Connected to an USB 3.0 port) but as you said, the problem seems to deal with power output of the USB port.
I have ordered other laptop models to test them and see if I can get better results than with our Dell : Acer Aspire ES15 (thanks for the reference ) and Lenovo V110.
I will update you on the results.
(Using a headset to take measurements was actually an idea from our geek-podiatrist but I'm not convinced our clients regular-podiatrists would jump into )
Have you tried the fixes recommended in this post for the connectivity issues? It has worked well for us, though a bit awkward to do on devices you don't own (having to do it remotely for clients etc).