User`s guide

42 DC 900-1339H
FMP Programmer’s Guide
3.3 Overview of DLI Functions for FMP
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)
Table 3–3 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.