To process a multivolume direct data set (BDAM) with EXCP, use the open routines to build a data extent block for each volume. Your program can do this by reading in the JFCB with a RDJFCB macro instruction and opening each volume of the data set with a separate DCB. See Using BSAM or EXCP for Random I/O to a Multivolume Data Set for an example of how to code a routine to do this, and Reading and Modifying a Job File Control Block (RDJFCB Macro) for further uses of the RDJFCB macro.