IDOc not getting generated while PO Output processing

Hi Guys,

we are started using IDOCs for sending POs to vendor.

We have seperate Output type for this with transmission medium EDI.

While processing Output for PO in message tab, Systme is processing it correctly(turning light Green) but when i see in processing log, i see that message 'IDoc '0000000000000000' was created and forwarded for transmission"

and there is not IDOc generated.

Please help me with this