User guide

9: Client Applications — Commands and Responses
DC 900-1338I 187
9.3 Additional Command Types Supported by the SPS
In addition to the API function calls described in the preceding sections, the SPS sup-
ports a few commands that are used by layers that lie between the SPS and API layers.
These commands are described in the following sections.
9.3.1 Internal Termination Message
The dlTerm function call is used by a client application when it loses its connection to an
ICP. The API issues the
dlTerm function call and provides the return node number to be
terminated. The SPS responds by clearing link active flags, turning off devices, and free-
ing session numbers for all links that had been communicating with the client applica-
tion using that particular return node number.
The following is an example of the format of the ICP and protocol headers received by
the SPS:
ICP_HDR
count = size of protocol header (16 bytes)
command = DLI_ICP_CMD_TERM
params[0] = node number to be terminated (ACK returns on this
node as well)
PROT_HDR
command = DLI_ICP_CMD_TERM
After performing the dlTerm call, the SPS returns an acknowledgment on the node that
was just terminated. This tells
msgmux or the ICP driver that the dlTerm call completed
successfully and the node number can be reused.