Welcome to the forums zhhpei.
Looking at the webpages for ONVIF, it appears to be an open standard that uses SOAP and XML.
Since you do not need to become a certified device, just talk to a device, you should be able to do this from a PAC Controller.
OptoMarys post on Communications Handles is a great place to start;
Simply put, you will open a comm handle to the AXIS device and then send and receive commands that control it.
You will need the command list and some documents from AXIS to do this, but they appear to be on their website, so that is the place to start.