just a random pick
JCL Abend code : S030
The error occurred during processing of a basic index sequential access method (BISAM) or queued indexed sequential access method (QISAM) OPEN macro instruction.
The control program found that the DCBMACRF field of the data control block (DCB) did not indicate a valid mode of operation for BISAM or QISAM. The DCBMACRF field is set up by the MACRF operand of the DCB macro instruction or by the problem program before the data control block is opened.