On Sun, May 27, 2012 at 6:47 PM, Jean-Michel Pouré - GOOZE <[email protected]> wrote: > My question is about USB connection/disconnection. The USB hubs have a > separate AC/DC. If I connect a hub with 7 readers, in some cases, it may > connect and then disconnect. The light on the hub blink and then are > disabled ... one by one, maybe one every second.
I have worked in a project where we needed the max possible amount of readers to build a SAM server. We ended up with 104 readers + 20 hubs (looks like the usb device limit is 127). The main problem was that the motherboard was not able to provide enough power for all the readers so we elected 4 usb hubs that were powered externally. Each of these main hubs are connected to a different motherboard usb port. On each main hub we connected 4 other hubs. So we ended up with 16 secondary hubs with 6 or 7 readers each. Some cheap brands of hubs bought from dealextreme could not handle that amount of readers, specially some fake 7 port hubs which are in fact 2 hubs of 4 ports interconnected. You should try other brands of hubs if you have problems with power and disconnection. You can always look at dmesg to see if the readers are getting recognized/disconnected. > Kind regards, > -- > Jean-Michel Pouré - Gooze - http://www.gooze.eu Hope it helps, Bruno _______________________________________________ Muscle mailing list [email protected] http://lists.drizzle.com/mailman/listinfo/muscle
