Patent ID: 7937504

Claim:
A computer program product for processing a chained-pair linked transport control channel program at a control unit configured for communication with an input/output (I/O) subsystem in an I/O processing system, the computer program product comprising: a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: receiving a first command message at the control unit from the I/O subsystem, the first command message specifying that a device command word (DCW) list is encoded in a data message associated with the first command message as part of the chained-pair linked transport control channel program; receiving a second command message at the control unit from the I/O subsystem chained-pair linked to the first command message, the second command message specifying data attributes associated with the DCW list; extracting the DCW list from the data message in response to receiving the data message; and executing the DCW list.