User`s guide

112 DC 900-1340I
BSC Programmer’s Guide
5.3 Overview of DLI Functions for BSC 2780/3780
This section summarizes the DLI functions used in writing a client application. An
overview of using the DLI functions is:
• Start up communications (dlInit, dlOpen, dlBufAlloc)
• Send requests and data using dlWrite
• Receive responses using dlRead
• For blocking I/O, use dlSyncSelect to query read availability status for multiple
sessions
• For non-blocking I/O, handle I/O completions at the software interrupt level in
the completion handler established by the
dlInit or dlOpen function, or by periodic
use of
dlPoll to query the I/O completion status
• Monitor errors using dlpErrString
• If necessary, reset and download the protocol software to the ICP using dlControl
• Shut down communications (dlBufFree, dlClose, dlTerm)
Ta ble 5 –3 summarizes the DLI function syntax and parameters, listed in the most likely
calling order. Refer to the Freeway Data Link Interface Reference Guide for details.
Caution
When using non-blocking I/O, there must always be at least one
dlRead request queued to avoid loss of data or responses from the
ICP.