Garmin Edge 510 pairing with in power meter

I have garmin edge 510. During the last training I lost my connection wiht my power meter. When I try to connect my power meter (in power 3D+) with the garmin, the garmin does not recognise my power meter. I change the battery in power meter, still does not work. Than I try to enter manually enter ANT ID in the garmin, still does not work. I am doing something wrong? Thanks for help.