User`s guide

3: BSC 3270 DLI Functions
DC 900-1340I 83
3.5.1 Normal and Transparent Received Data
The BSC 3270 software provides four read codes for data reception: two for normal
data (
DLI_PROT_SEND_NORM_DATA and DLI_PROT_SEND_NORM_DATA_EOM) and two for trans-
parent data (
DLI_PROT_SEND_NORM_DATA and DLI_PROT_SEND_NORM_DATA). For efficiency,
normal data sometimes contains multiple messages from the serial lines in a single mes-
sage buffer.
3.5.2 BSC 3270 Sense/Status Message
When a control station receives a BSC 3270 sense/status message from a tributary link,
it reports that message to the client. The client application performs a
dlRead request
and receives a data message with the
pOptArgs.usProtCommand field set to
DLI_PROT_SEND_PRIOR_DATA_EOM. The format of the message is:
% R S/S0 S/S1
where S/S0 and S/S1 represent the device status bytes. See Section A.4.4 on page 204
regarding BSC 3270 sense/status messages for virtual devices.
3.5.3 Error, Confirmation, and Acknowledgment Responses
Ta ble 3 –10 lists the possible BSC 3270 error, confirmation, and acknowledgment
response codes returned in the dlRead pOptArgs.usProtCommand field. All of the
responses, as well as the
DLI_PROT_RESP_ERROR error report, can return an error code in
the
dlRead pOptArgs.iICPStatus field to indicate failure.
3.5.4 Reports in Response to dlWrite Information Requests
After issuing a dlWrite information request (Section 3.4.2), a dlRead request must be
issued to receive the report information. The reports are listed in Tabl e 3– 10.