Only able to connect 42 USB devices

[Jacksleo]

I am trying to build a setup to read a lot of smart cards.

I have a dedicated USB controller card with 4 USB port which each should be able to run up to the 128 USB devices.

On 1 powered USB hub with 10 ports I have connected 6 USB smart card readers and 3 other powered USB
hubs with each 10 USB smart card readers so a total of 36 smart card readers.

This connected gives a total of 42 USB devices (36 readers, 4 hubs, 1 mice, 1 keyboard).

We have checked the power setup and the powered USBs is providing fine.

It runs without any problems at all on any of the USB controller ports.

Connecting one more USB device of any kind results in it not loading. A reboot with the unit connected gives a random USB unit failing but the removing any other will bring that one up.

So it seems like somewhere theres a blocker at 42 USB devices any who know if there is such a thing in windows?

 

[Layback Bear]

This post is a joke right.:roflmao:

 

[Jacksleo]

Ofc its not a joke.

Have around 250 smart cards to be hosted 24/7 but sadly they have to be on windows machines.

If I can only get the 36 I need 7 machines running them and I was only counting to have 2.

 

[Lady Fitzgerald]

Forgive my curiosity but why do you need to access so many cards at once?

One possible bottleneck may be the USB controller card itself. If the card is running off just one PCI-e lane (which means the vast majority of cards), then each USB port on the card will be running at no more than 1.25GB of bandwidth when all ports are being drawn on. Also, even when using powered hubs, you can daisy chain only so many before getting shut down.

Also, many of us don't speak textese and I, for one, do not appreciate having to look up texting shortcuts like ofc. If what you are saying is so vulgar as to require text abbreviation to "get away" with posting, mayhap you shouldn't use the expression at all. Jack's asking if your request was a joke is understandable considering you are a brand new poster and it is extremely unusual for someone to want to process so many cards at once (I've never seen it before) so there was no need for disguised profanity.

 

[Jacksleo]

I have that many smart cards I need to keep online.

The daisy max should be 128 on each main port and I also hit 42 if I use the standard USB instead of the installed card.

There is no active data transfer when Im connecting more readers so it should not block up on bandwith.

Its not a joke proberly gives you the meaning then. Never heard any making that kind of jokes and spending time to register to make them.

If there were answers or any experience on mass USB usage or of the 128 max USB that is said to be the max I wouldn't have to post but could use those answers. I doesn't get the point of the rest of your post so I guess this answer will have to do.

 

[Lady Fitzgerald]

I have that many smart cards I need to keep online...

That doesn't really tell us anything. Why do you have so many and what are you doing with them?

...Its not a joke proberly gives you the meaning then. Never heard any making that kind of jokes and spending time to register to make them...

We have, hence the question.

 

[Jacksleo]

Its digital tachograph company smart cards that you sync up with a truck drivers tachograph smart card to transfer the statutory truck driver informations.

 

[Lady Fitzgerald]

For something on this large of a commercial scale, you probably should hire an IT professional to set up a system for you to avoid possible legal issues.

 

[Layback Bear]

There has got to be a better way of doing this project other than this.

from post #1

This connected gives a total of 42 USB devices (36 readers, 4 hubs, 1 mice, 1 keyboard).

I understand that many trucking companies monitor many things from a truck on the road.
They surly don't have a bunch of usb devices hanging all over off of hubs and usb ports.

Jacksleo I would suggest you do some research on how other trucking companies do such things.

 

[Indianatone]

Technically you'll also be limited to a maximum of 24 drives per computer given that Windows is on the C drive and the CD/DVD is on D drive. That leaves you 24 drive letters so the machine can see and use the USB Drives. So by that issue alone you are going to need 11 PC's absolute minimum but I would suspect that it would be rife with problems. Not something that is a good idea, probably need more PC's that that for reliability. I would suggest a maximum of 10 USB drives per machine and that frankly would be pushing it.

 

[Jacksleo]

Lady Fitzgerald problem with those "professionals" at least the ones who have looked at it so far either thinks its a totally imposible project specially because its windows, eventhough they can se that its actually up and running now and processes data all the time. The rest are the classic not thinking outside the box but knows everything from specifications and every where windows can handle 128 devices per root hub. But they have never seen above 10 connections. So short im hunting for that windows geek who... in some state of drunkness found 80 USB mice just to test if you could run them all and figured out how to do it.

Layback Bear im not from a trucking company but a GPS tracker company and we sell a tracker solution including tacho connection in the truck. Customised Tracking Solutions - Powerful tracking devices with exeptionally flexible software - Flextrack if it should be of interest. We have a setup were we host the company card so that the tacho data can be transfered to the company without they have to access the trucks physical (that is how ordinary companies does) ofcourse there are rival companies who have chosen to build software so the companies host their own company card but we have choosen to take care of that part to with great success. The data is not transfered to optimise or stuff like that it has to be delivered to the goverment to be allowed to have a trucking company and this gives some of the problems as it ofcourse is protected data but all that is working on a legal setup currently. I have 2 machines running it currently where each machine have 36 active company cards with around 500 trucks connected through GPS trackers and it runs without any problems. But I would rather not have 5 machines more when it should be posible to run it on 2.

Indianatone I dont need to assign them as drives to work the key from them I just need windows to have them and install the driver and we have that working on 36 devices if you dont count the hubs and mice/keyboard. But your proberly close to the problem or at least my guess that there is some assigning somewhere with a limit way below 128.

 

[AddRAM]

Connect as many usb cards and usb hubs as you can to the PC

You need a board with like 6 or 8 free pci slots.

Hook a 4 port usb card to each one of those, the possibilities are endless, well, not endless

 

[logicearth]

Just to let you know, the daisy chain limit for devices is 127. However the daisy chain limit for usb hubs is 5. Next the usb card you are using in the system likely has its own limitations as well, you should look into those.

Try connecting the 4 usb hubs directly to the usb card itself.

 

[Layback Bear]

I do wonder how companies like Yellow, Schnider, Fedex or UPS use for their trucks.
Do they have a bazillion usb hubs with who know how many smart cards plugged into them.

The last person I knew that drove a Punkin (Schnider) truck had a dome on the cab that transmitted all kinds of information to the home base including internet and G.P.S. and lots of information about the trucks.

 

[Jacksleo]

logicearth the one hub with 3 hubs is the working part. But when I then connect just one more smart card reader to either "the one hub" another port on the dedicated USB card or one of the computers ports its not found. Just tested this morning moving the hubs to dedicated ports and same result. I also tried connecting a mouse instead and that is not found either.

Layback Bear I think you misunderstand a bit. The digital tachograph which you legally have to have in the truck has its own smart card reader built in so its only the single company card which have to be connected to the truck card I have on readers. But yes in big companies theres a lot of cards in play.

 

[TVeblen]

You have entered PC Twilight Zone. Where modern needs run smack up against old programmers.

The 128 devices on a USB daisy chain is a theoretical maximum. Remember that term - it will be back to annoy you many more times in your digital life.
The reason is because the USB devices must be given 'addresses' to be recognized, and those addresses are stored in 7 bits on the register. (Why 7 bits? Because space is precious and why would anyone ever need more - in 1994). So there are only 128 possible addresses that can be made with only 7 bits. And the PC's USB controller is one device so that leaves 127.
127 devices can be named. That does not mean that 127 devices can be run.

Because then there is Bandwidth. And that is where I think you are running up against it. There will be a limitation in the number of devices that can be communicated with along the same line due to the limitation in Bandwidth.

USB 2.0 has a theoretical maximum (there it is again!) bandwidth of 480 Mb/s and if you exceed the (real world) maximum the chain will fail.