DALSSREQ requests that a subsystem data set be allocated and, optionally, specifies the name of the subsystem for which the data set is to be allocated.
When you code DALSSREQ without specifying a subsystem name, # must be zero and LEN and PARM are not specified. The data set is then allocated to the primary subsystem.
When you code the subsystem name in the DALSSREQ key, # must be one, LEN is the length of the subsystem name, up to a maximum of 4, and PARM contains the subsystem name.
KEY # LEN PARM
005C 0000 - -
KEY # LEN PARM
005C 0001 0004 D1 C5 E2 F2