Distributed 5250 Emulation Model
The Virtual Terminal Client/Server Model example shows a model for a distributed systems environment between a workstation and a System i® platform. The client program resides on the workstation, while the server program resides on the System i platform. This model is similar to the way the system supports an IBM® i Access workstation function.
Virtual Terminal Client/Server Model Example
The client program running on the workstation shown in the example does the following:
- Accepts data from the server program and displays the data on the workstation display
- Accepts data from the workstation keyboard
- Converts the data from the format required by the workstation display and keyboard to the format required by the server program (5250 data stream)
- Sends the data to the server program
The link between the client program and server program uses DOS and IBM i communications support. This may be LU 6.2, TCP/IP, or some other communications protocol.
You can write a server application program in any IBM i-supported
high-level language (HLL), such as the ILE C programming language. The server
program provides workstation support for the system acting as the server. The
virtual terminal APIs allow a server program to read and write virtual terminal
data. Virtual terminal data is always in a 5250 data stream format. See the
IBM 5494 Functions Reference manual, SC30-3533, for more information
about 5250 data streams. This manual can be viewed online through IBM
Publications Center
.
The virtual terminal APIs provide an interface between the server program and the virtual terminal. The virtual terminal represents the link between the server program and the IBM i application and is managed entirely by the IBM i operating system.
The IBM i application can be a licensed program or a user-written application that performs a standard data transfer to a workstation. This application can be written in any IBM i-supported HLL.