Select Link3270 client scenarios
The following scenarios describe some common client environments.
- Business client
- The business client is concerned only with the business data and its representation in the client end-user environment
- bridge client
- The bridge client builds the bridge messages and manages the communication with the bridge using the Link3270 interface. You can develop the more complex bridge client to run in CICS® , using CICS commands, and the business client portion can run in any environment that allows communication with the bridge client. The bridge client can be designed to be reusable.
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Host
CICS
Client
In this scenario, shown in Figure 1 , the programmer has CICS skills and experience, so it is more appropriate to write the Link3270 interface code on CICS.
You can separate the client logic into a business client, and a bridge client.
The LINK and EXCI samples show how a client application can be separated in this way and how common logic can be shared in the bridge client. Note that a business client in another CICS region can use DPL to access the bridge client.
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CICS
Workstation Client
In this scenario, shown in Figure 2 , where a CICS product is installed on the workstation ( such as CICS for Unix) then the client can be a CICS program using LINK to interface with Link3270, or with a host CICS bridge client. In the three tier model the writer of the bridge client needs to have CICS skills, but the business client programmer only needs skills on that platform.
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Non -
CICS
Workstation Client
In this scenario, shown in Figure 3 , the programmer has workstation skills and limited CICS experience. For the two tier scenario, the programmer must have some CICS experience to understand the messages (which involve EXEC CICS instructions).
The client program executes on a remote workstation, using ECI to drive the user application. A single client program is written, combining the business logic in the client environment and the interface to Link3270.
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3–tier Workstation client
In this scenario, shown in Figure 4 , the workstation business client calls a bridge client in another environment, perhaps to utilize existing skills. For example, a Unix program could send a user-defined XML message to WebSphere® on z/OS® . A user-written bridge client application in WebSphere could then parse the XML message and convert it to a Link3270 message and use an EXCI LINK to call Link3270.