Using USB hubs

I got my RCM5700 deluxe development kit, got it all set up, loaded the software and found that programs would compile & run about one time out of 25. The other 24 times I got a message like “While sending pilot bios an timeout occurred” or something along that line. A few calls to support, which were dropped on my end (thanks a million Verizon) didn’t help much. Finally I moved to my laptop so I could use another phone to call support, but everything worked there. The biggest difference was that on my workbench machine the USB cable was plugged into a hub, not direct into the system. It’s a powered hub that works fine with a propeller development system and an organic led, both of which use the same or similar FTDI-232 chip the RCM5700 uses, and Microchip PIC-32 & PIC-24 development systems that use other USB to serial chips, so I never gave it another thought, but it seems the RCM5700 doesn’t like going through a USB hub. It all works now, so I decided to post this before someone else gets bit the same way.

Thanks for sharing you tip, since I was starting to ask myself what was going wrong with my configuration.

I confirm that RCM5700 seems not very happy with USB hubs.

Did you have the wall power supply plugged in?
You don’t normally need it, but maybe with the hub, you do? Seems strange.

The RCM5700 was running from it’s plug-in supply, as was the hub. I’ve seen a few devices that came with documentation that stated specifically that they needed to be plugged directly into the system and not a hub. It may have something to do with time delays expected for a reply, going through a hub may slow an acknowledge down a nanosecond or two and mess up the software.