3. The computer program product of claim 1 , wherein the data check word generation field is a Data Check Word Seed field, and generating the at least one ACW includes inserting an initial value into the Data Check Word Seed field that is used to generate the at least one generated data check word corresponding to the data transfer request.
4. The computer program product of claim 3 , Wherein the I/O operation is a transport mode operation, and obtaining information includes obtaining a transport command word (TCW) at the channel subsystem, the TCW including a transport command control block (TCCB) address field including an address of a TCCB, the TCCB including a plurality of device command words (DCW) that each includes an I/O command.