For Bosch Rexroth Drive, the PDO's have to be written to the drive memory through TrioBASIC program in Pre-op. If not the drive will not switch from Pre-OP --> Safe-OP. You will require a program & EC_EXTEND file (included in the attachment)

Use the INDRAMAT software, extracted the SDO data written in the Drive memory (also included in the attachment). Download this to the drive and run the SETUP_PDO.bas to initialize the Ethercat