User`s guide

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BSC Programmer’s Guide
depending on the setting of the modem control option, Section 6.15 on page 168) from
the remote end. The link is not considered started until this signal is received. If you are
using non-blocking I/O, you must also make a
dlPoll request to read the completion sta-
tus of the command.
An unsuccessful Start Link command can return one of the following error codes in the
dlRead pOptArgs.iICPStatus field (see Appendix D for error handling):
DLI_ICP_ERR_LINK_ACTIVE
The link is already started.
DLI_ICP_ERR_BAD_MODE
The function request is not available for the requested
access mode.
DLI_ICP_ERR_BAD_PARMS
The parameter value(s) used for the function call are
illegal.
5.4.1.6 Stop Link Command
Use the dlWrite function with the pOptArgs.usProtCommand field set to
DLI_PROT_SEND_UNBIND and the pOptArgs.usICPCommand field set to DLI_ICP_CMD_UNBIND to
stop a link without ending your session with Freeway. This command turns off the DTR
modem control signal and shuts down the link transmitter and receiver. A Stop Link
command can be sent to a link that is active or already inactive.
A call to dlClose (described in the Freeway Data Link Interface Reference Guide) also
stops the link, but terminates the session as well. This is the normal method to termi-
nate a session at the end of a client application. The Stop Link command is useful for
temporarily stopping the link without terminating the session (for example, to recon-
figure the link using the Link Configuration command). The link is restarted again by
issuing a Start Link command.
For blocking I/O a successful Stop Link command returns zero, but you must call
dlRead to receive the DLI_PROT_RESP_UNBIND_ACK response indicating the link is deacti-