DALSECND specifies a secondary space quantity. You must also code one of the space type keys (DALBLKLN, DALCYL, DALTRK) when you specify DALSECND. When you code this key, # must be one, LEN must be three, and PARM contains the secondary quantity value.
KEY # LEN PARM
000B 0001 0003 00 00 0A