[asterisk-users] Question on system command 1.4.43

[Jerry Geis]

I have a USB to serial converter attached to my box.  pl2303: Prolific 
PL2303 USB to serial adaptor driver
if I login to the box and send/receive serial commands over this unit it 
works without error EVERY time.

however, if I run the same command set from with-in the extensions.conf 
with System()
I get errors in dmesg like "pl2303 ttyUSB0: pl2303_open - failed 
submitting read urb, error -22"
and then obviusly my command does not work.

however, again - If I go back to the command line and my command it runs 
just fine.

Any ideas on what might be happening here?

Jerry

extensions.conf
exten => s,1,ChanIsAvail(Console/Dsp)
exten => s,n,GotoIf($["${AVAILCHAN}" = ""]?smvoice-busy,s,1)
exten => s,n,System(/home/silentm/bin/usbserial -start)
exten => s,n,Playback(beep)
exten => s,n,Dial(Console/dsp)
exten => s,n,Hangup
exten => h,1,System(/home/silentm/bin/usbserial -stop)