Hi,

I am trying to get a ST lab USB-SERIAL-4 adapter working under Red HAt Enterprise Linux 4 update 4.

The kernel version is 2.6.9-42.ELsmp

The device is correctly detected by the kernel and the device /dev/ttyUSB0 is created automatically.

==> cat /proc/bus/usb/devices

results in:

T: Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 0
D: Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=067b ProdID=2303 Rev= 3.00
S: Manufacturer=Prolific Technology Inc.
S: Product=USB-Serial Controller
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=pl2303
E: Ad=81(I) Atr=03(Int.) MxPS= 10 Ivl=1ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=83(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms

(I have only copy+paste the section of the report detailing the usb to serial device.)


Now if I try the following:

==> echo "test" > /dev/ttyUSB0

I get a result on the other end of the cable. I.e. data is output through the port. Unfortunately if I repeat the command the command just hangs forever and no data is transmitted.

If I reboot the command will work again only once.

Anyone have any idea why the device is not working correctly?

Cheers,

Stvy