DT510 specific errors are usually due to the assembly. It can be identified by the fact that the flashing signal 1-5-2 is returned immediately when a transponder is presented after the battery has been changed.
When the electronic knob is mounted on the profile cylinder, the electronic knob can read transponders and operate the profile cylinder's clutch.
When mounting the cover of the knob, however, the sealing ring on the profile cylinder may detach the knob from the contact surfaces on the profile cylinder.
After changing the battery, it can therefore often happen that the electronic knob loses contact with the profile cylinder.
You can easily check the installation with the help of this video.