Changing HPDM agent pull interval

Hi,

How do I change the default agent pull interval? I know I can do it manually from the control panel on the client, or directly from HPDM, but since i can't send tasks to the client the latter won't work. 

I tried changing it on the client to 30 minutes, then caputring an image and deploying it to a new client, but the pull interval reset itself to 1 day.