Eric,
Follow/verify below.
Condition type for order type NB, function = VN, A = ALE and 4 = Send immediately (when saving the application)
Partner profile for vendor - type LI for vendor 1110000022,
Note few parameters like partner roles VN, output mode = "trigger immediately" and two lines in message control tab one for create other for change of PO.
Output (IDoc) for create/change.
Best,
Abhijith