A data recording apparatus, which is capable of acquiring and recording data according to the residual capacity of the battery when the residual capacity is small. When image processing to be executed by a specific image processing unit identified based on the identifier is switched to another image processing, an image processing unit which has received packet data changes the identifier contained in the packet data, and transfers the packet data containing the changed identifier to another image processing unit. The terminus may be formed as an anchorment for anchoring to the container.