User`s guide

1: Introduction
DC 900-1340I 31
1.4.2 Opening a Session
After the DLI and TSI configurations are properly defined, your client application uses
the
dlOpen function to establish a DLI session with an ICP link. As part of the session
establishment process, the DLI establishes a TSI connection with the Freeway MsgMux
through the TCP/IP BSD-style socket interface for the Freeway server, or directly to the
client driver for the embedded ICP environment.
1.4.3 Exchanging Data with the Remote Application
After the link is enabled, the client application can exchange data with the remote appli-
cation using the
dlWrite and dlRead functions.
1.4.4 Closing a Session
When your application finishes exchanging data with the remote application, it calls the
dlClose function to disable the ICP link, close the session with the ICP, and disconnect
from Freeway (or the embedded ICP).
1.5 BSC Product Overview
The Protogate Binary Synchronous Communications (BSC) product is a software pack-
age that allows applications running on the client to communicate through one or more
serial links to devices using the IBM BSC 3270 and/or BSC 2780/3780 protocol.
Each BSC serial link handles all low-level protocol activity thus freeing the client com-
puter to perform other tasks. User-written client application programs interface to the
BSC software through the Freeway DLI.
Each BSC serial link can be configured as a 2780/3780 link, a 3270 control station (sim-
ilar to an IBM 3705 communications controller) or a 3270 tributary station (similar to
an IBM 3274 cluster controller). Each link operates independently of other links on the
same server and can be configured with different communication options.