Installation guide

DC 900-1564A 57
Chapter
5
Header Formats
The application and the SLC protocol software on the ICP communicate by sending
commands and responses. This chapter identifies the format of each command and
response. Table 5–1 on page 58 gives an overview of the categories of commands and
responses used by the SLC protocol. The individual header formats are presented alpha-
betically by command/response name in Section 5.1 through Section 5.16.
Figure 5–1 gives the “C” definition of the optional arguments structure (
DLI_OPT_ARGS)
used when making calls to the DLI interface. Figure 5–2 shows a typical definition of
the comparable structures used when making calls directly to a driver interface.
Table 5–2 compares the fields used to interface to the DLI versus a driver and also gives
a general overview of the typical field values used for the SLC protocol, though there are
some request-specific differences noted in the following sections. Refer to the Freeway
Client-Server Interface Control Document for using the socket interface.
Note
Most of the fields within the ICP_PACKET structure are in network
byte-order. However, each field name that starts with “
usProt” or
“
iProt” is in client byte-order. The client must declare its byte-
order characteristics in the
iICPStatus field of each command
when making non-DLI calls.
Leslie...look
into finding or
creating a
similar table
for the socket
interface...
later.