How to create PO Acknowledgement (855 EDI) outbound

Hi,

I am SD guy ,want to create PO Acknowledgement and generate IDOC number for different partners which have been provided by Client. Am not sure how to create PO Acknowledgement at the same time don't know how to trigger IDOC numbers for the PO acknowledgement for partners.

Could anyone provide me the process for creating PO Acknowledgement in ECC.

Before posting here have done groundwork but I couldn't understand.

Please do the needful . Points will be given for

Regards

Kiran