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Cable lengths

Hi all,

I am not far off adding a message with my trials and tribulations with regards to USB. In my research I came across a beaut website that summarised the maximum lengths allowed for all types of cabling. Well worth a look and bookmarking.

The reason it is relevant is because once you build your cockpit you will need to have your computers in close proximity. In my case I have four and the average distance from the computers to the front of the shell is about 5-6 metres ( 15-18ft). I can tell you in my case whilst flying I need to swivel my head outside the cockpit to glance at the screens for various reasons. One might be to change the weather on the fly. In that case the computer screens need to be behind the shell and to the right assuming you'll use the Captain seat the most. Therefore that is the reason for the distance required for the cabling.


Food for thought for most of you.

Hope the link works and you find it helpful.


Mark Speechley



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Thanks Mark!

Good information and a great guide to cable lengths.  At a quick glance, this guide confirms what I already knew:  The weak link in cable lengths is our USB cables.  It's tolerance for loosing signal and creating issues is much less than the other types of cables we use.

I once read that the maximum USB cable length can not exceed 12' 4" without a powered USB hub or signal loss will occur and bad things will happen.  The funny thing is in my case, I tried to do the right thing and use a powered USB hub to boost the signal and used a 10' long cable from the computer to the hub and a 5' cable from the powered hub to the interface device.  It did not work!  But when I tried a 15' USB cable it did work with no further issues.  (15' is about 5 meters)

Unless you are setting up your sim in a remote garage and setting up your computers in your house,  in other words, a really long distance away from one another, the weakest link in the cable length question is always going to be our USB cables.  The guide you have point to Mark is a great tool that helps illustrate this and trouble shoot any potential problems.

Great looking photo of you hangar bay by the way!  Looks awesome and I bet a joy to fly!

Funny you should mention that even with the powered hub and the 10' cable you were still having problems.

I kid you not. I must have been hit with the windows update stick about 6 weeks ago as I have just had a cascade of USB problems from the four computers. It might have been a self fulfilled prophecy with problems with one computer, then mix and matching different hubs and cables to fix computer one and you end up 'spreading the love around' to the others !

Fortunately I have hit on one fix that you should all store away for a rainy day. Apart from the aforementioned cabling advice from Ron and I, it is a simple windows based fix that may help.

1/ Open up your power plan. Depending on which Windows you have,( which determines where to find it ) go to Power Options and then Edit Plan Settings. Look for Change Advanced Power Settings.

2/ Scroll down to USB Settings and click on the + sign in the little box

3/ Click on USB Selective Suspend Setting. Change setting to Disabled.

4/ Click Apply or OK to save.

The USB selective suspend feature allows the hub driver to suspend an individual port without affecting the operation of the other ports on the hub. Selective suspension of USB devices is especially useful in portable computers, since it helps conserve battery power. In reality what seems to be happening is it can be suspending usb ports and not re-enabling them giving you less usb ports to choose when re-plugging in usb cables.

Worth a try if you haven't had success changing cables/hubs and have uninstalled the usb controller drivers in device manager, with no success.

Mark S.

Well continuing on with the theme of USB issues and cables.

I have had endless problems with USB disconnections this year and have tried to resolve the issues by changing cable types ie USB 2.0 and USB 3.0.I have tried alternating hubs from powered to non-powered. I have tried powered USB 2.0 and 3.0 hubs. finally I narrowed the problem down to my Saitek pedals. I have 2, however one was disconnecting and 'freezing' the mobo, as seen by the clock frozen. Interestingly enough though in P3D 4.2 the Lear would keep flying and the mouse moved with a frozen mobo ! The USB peripherals attached would not function any further and only a hard reset would restore the computer.

The one pedal was throwing up the occasional windows error that there was an overvoltage in the usb port. Oooh not good. After extensive reading the advice was you can right click to go into properties for that usb port and turn off the warning ! Not the best safety advice but it turns out that the tolerance by windows is too sensitive for that slight increase so should be safe.

So what was the fix for the pedal ? Well if you disconnect and reconnect the pedal in the usb hub then windows looks for a saitek driver and loads it OR goes to windows update for it's own driver. The old saitek driver was suspect in the first place with all the windows updates, so I downloaded the 'latest' updated driver from the last 12 months from Logitech. Well when you install the new driver,it doesn't 'take' as windows is still using it's driver which is faulty. So you disable the usb ports for the pedals and reboot. Upon restarting windows defaults to downloading it's windows update saitek driver which is 2010 vintage. If you quickly click on an option in the dialog box to stop downloading and look locally it will find your new driver and load it. Job done. Most of my grief had boiled down to windows and drivers. So the take home message is don't be too hasty to change out your hardware.

Here is an interesting bit of further advice from Rob Ainscough moderator at AVSIM and Prepar3d, given  July 30th 2018, given to another chap with another brand of pedals'  issues. This is worth stashing away in the knowledge base.

Have you added another USB  device recently?

Connecting disconnecting is a sign of too many USB devices on a single USB chipset where they aren't all getting sufficient power.

An easy test would be to buy a USB 2.0 PCIe card (they're very cheap) and add it to your system and plug the MFG Crosswind into the PCIe card (alone).

Typically I get about 12 USB devices per chipset (regardless of powered hubs or not).

Cheers, Rob."

Interestingly enough the guy with the problems sorted his out by changing the cable. And around we go.

Hope this one day will be of help to someone out there.


Mark S.

Thanks Mark for the info!  I am hoping that with all this knowledge that we are collecting we can stay on top of it all.  Remember, the new path is going to be several Arduino interface cards.  Hopefully we will not have the same type of issues with USBs as we do now.

"Hit and miss" or "keep your fingers crossed" is not the best way to go about interfacing our cockpits!  Getting rid of the Pokeys should resolve most of these issues for us.

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