Installation guide

3: Interfacing to DLI/TSI and Protocol Software
DC 900-1325I 53
Note
When using non-blocking I/O, a read request must be queued to
receive the Local Acks. The read buffer associated with this request
remains queued.
If your SRA is using DLI Raw operation, or if you are using a protocol that requires Raw
operation, then you will need to handle the Local Ack packets from within your SRA. If
you are using Normal operation, but still want to handle the Local Ack packets within
your SRA, you need to put the following line in the port definition section of the DLI
configuration file:
localAck = “no”;
Otherwise, the DLI will “eat” each of the Local Ack packets before the SRA can see them.
3.2.5 Optional Arguments
Once the DLI session has been opened for a link, the SRA may transfer data on the link
using dlWrite and dlRead library calls. These calls normally include an “optional argu-
ments” structure (also known as “optargs”) that contain additional parameters related
to the dlWrite or dlRead call. Normal operation will allow you to omit the optargs struc-
ture when sending and receiving data. However, Protogate recommends the use of
optional arguments in the dlWrite and dlRead calls when writing and reading data on
the serial line, especially when using the more “complex” protocols. The reason is that
most protocols provide additional information in the optional arguments structure that
may be essential to the status of the serial line. The SRA may miss this information when
using read and write calls without optional arguments.
3.3 Modifying the DLI Configuration File
If you run your SRA from the Freeway operational directory (/tmp/boot), it may be
beneficial for you to automate the regeneration of your DLI configuration binary file.
The advantage here is that you will be able to change individual link configuration