Technical data

54
W&T
If 0x01 or 0x04 was received, the actual data connection can
be opened.
SrcPort
The client application alwlays enters a 0 here.
The Web-IO returns here the opened server port (e.g. 49153 for
Binary 1). If the login attempt has failed, the Web-IO enters 80.
DestPort
The client application enters here which port will be used for
the connection (e.g. 49153 for Binary 1 or 49154 for Binary 2).
The Web-IO always returns 0.
The connection through which the BinInfo structure was
transmitted is automatically closed by the Web-IO.
3.8.6 BINARY - The IO structures
To enable simple communication between the user program on
the computer and the Web-IO, there are a limited number of
structures (variable fields) which define the format and content
of the data exchanged between the user program and the Web-
IO.
IO structures are provided for the following functions:
. Reading the inputs
. Setting the outputs
. Parameterizing the cyclical and automatic messaging when
there is a status change
The user program uses the easy to use socket4 interface
(Windows: WinSock, UNIX, Linux: Berkley Sockets) for
exchanging data in the form of these IO structures with the
Web-IO over the network via TCP/IP.
The IO structures do not depend on the network protocol used
(TCP or UDP).