SDISC Assembler Call - NetEx

Transmit Message and Data – DWRITEThe driver takes transmission requests and sends them over the network in FIFO order. The driver caller isentirely responsible for the contents of the network message and its associated data. Because of the half duplexnature of the adapter, the driver will service input requests before output requests. Since a single hardwarepath through the network is specified in the call, retry over alternate routes is the responsibility of theapplication.H307 does not support intra-host driver-level requests. Information may be sent to another driver-level useron the same host only if a hardware path is available.Operation ParametersDWRITE[W] nrb [err-return]DWRITEThis is the required procedure name.DWRITEWIf specified, control will not return to the caller until the request is completed. Otherwise, return willbe made immediately after a preliminary error check of the request.nrbThis is the required address of the updated NETEX request block (NRB) that is to be used with theprocedure. This field may have the following form:U-field[,X-reg[,J-desig]]err-returnThis optional parameter is the address for transfer of control if the request completes with an error indicationin NRBSTAT.DWRITE Entry ParametersThe following NRB fields are used by DWRITE on entry:NRBNREF The DREF for the desired connection, as assigned by DCONNECT.NRBREQSet by the procedure to DWRITE.NRBPROTA Address of the message proper to transmit.NRBPROTL Length of the message proper to transmit.NRBBUFA Address of the associated data to transmit.NRBLENLength of the associated data to transmit.NRBUBITNot used; set to zero (always sends full words).NRBDMODE Specifies assembly/disassembly and code conversion.DWRITE ResultsThe following NRB fields are updated when DWRITE completes:NRBSTATRequest status: -1 ‘in progress’; 0 ‘successfully completed’; otherwise a positive nonzeroNETEX error code.MAN-REF-H307IP-04 Driver Interface Page 73