sendmodem blocked

[GoogleCodeExporter]

I want to use sendmodem to send command to baseband(/dev/tty.debug). But it 
block as below, seems never stop or receive some information. Any one can help 
me? Thank you in advance.

sendmodem "AT+XGENDATA"
Sending command to modem: AT
----.....................+
----...............+
----.....+
----...............+
----.............................+
----..............+
----...................................+
----...............................+
----...............+
----........+
----.......................+
----...............+
----.......................................+
----............................................................................
........................................................+
-.+
---............................................................+
----.....................................+
----............................................

Original issue reported on code.google.com by dirk...@gmail.com on 24 Aug 2012 at 2:22