SDISC Assembler Call - NetEx

Data TransferUnlike the rules for establishing a session, NETEX provides a lot of flexibility in how session requests areused for the data transfer process. The following sections describe two methods for programming data transfer.The first method is a basic data transfer technique, the second uses the more advanced technique of concurrentSWRITE and SREAD requests.Write/Read Data TransferThe following paragraphs describe the session requests that are used to transfer data in a straight-forwardway. Usually, calling programs use the SREAD and SWRITE requests to perform the data transfer. The figureshows how the calling programs perform the data transfer. SWRITE requests are issued by one programwhich must be received by an SREAD issued by the other program.Figure 6. Write/Read Data TransferThe following numbered items describe the steps in the figure above. The steps are numbered to simplify thediscussion and do not necessarily represent the exact order which the events occur.1. After a session has been established, program A issues an SREAD. The SREAD specifies the buffer forreceiving data.Page 14 Intertask Communication MAN-REF-H307IP-04