Error message mes when trying to send PO via IDOCS to another system?

Hi Abap expert,

I am getting wired message what I ma trying to send PO via IDocs to other SAP system.

I went to all partner , port configurations on WE20 and everything there seems to be fine but once I go to ME23N, then GO TO -> MESSAGES , than opens another windows when you key in MESSAGE CONTROL DATA that have been mantained

in the outbound parameters in the PARTNER PROFILE configurations.Then I am getting the message :

-

'No communication data has been defined for transmission medium 6'-----

The LED on "PO:output screen' is YELLOW and never gets green.

Can someone tell me how to overcome this and send my PO Idocs?Please some more details will be appreciate it!

Thank you much eveyone!

Boby