The primary function of an access method driver is to receive service requests, send the service requests to servers, receive service replies from the servers, and send the service replies back to the requester. Service requests must be sent to servers in a CPRB control block.

To send a service request, you can use the CHSDCPRB macro to create a CPRB and the SENDREQ macro to initialize the CPRB with the request and send it to the server. For details, see SENDREQ Macro. The SENDREQ macro sends the service request in a CPRB as shown in Table 1.