Unable to print with SerialPort

[Jayacharan Rampog]

Hi,

i am using cups-1.2.12 with Debian Linux-2.6.18,i have developed driver for my printer it's working fine with parellel port,

when i am trying to print with serial port it's giving error like this what may the problem, let me know please.

error_log:


root$vim /var/log/cups/error_log



I [30/Jan/2009:15:09:38 -0800] Job 130 queued on "ltp2001" by "guest".
I [30/Jan/2009:15:09:38 -0800] Started filter /usr/lib/cups/filter/pstops (PID 3547) for job 130.
I [30/Jan/2009:15:09:38 -0800] Started filter /usr/lib/cups/filter/pstoraster (PID 3548) for job 130.
I [30/Jan/2009:15:09:38 -0800] Started filter /usr/lib/cups/filter/rastertoescpos (PID 3549) for job 130.
I [30/Jan/2009:15:09:38 -0800] Started backend /usr/lib/cups/backend/serial (PID 3550) for job 130.
E [30/Jan/2009:15:09:38 -0800] PID 3550 (/usr/lib/cups/backend/serial) stopped with status 1!
I [30/Jan/2009:15:09:38 -0800] Hint: Try setting the LogLevel to "debug" to find out more.
E [30/Jan/2009:15:09:38 -0800] [Job 130] Unable to open serial port device file "/dev/ttyS0": Permission denied
I [30/Jan/2009:15:09:38 -0800] [Job 130] Backend returned status 1 (failed)
I [30/Jan/2009:15:09:38 -0800] Saving printers.conf...
I [30/Jan/2009:15:09:40 -0800] commptr=""