This Block Tag is used specifically for filling data fields in a frame for sending later. When filling an Element in this Block Tag, the corresponding data in the frame is automatically updated, if the value is valid for that field. This is a write-only Block Tag. The number of Elements of this Block Tag corresponds to the number of Data [DT]-type fields configured in the Field Type option.

The result of this Block Tag's writing is a read-only list whose size varies from 1 (one) to 256, as configured in the Max Accepted Answers option, containing the most recent valid frames received between the current reading and the last reading.