A UAP in client/server mode can call and use the program of another process. Units of programs which can be called and used are called services. Processes which provide services are called servers. UAP servers are called user servers.

UAPs in client/server mode are categorized into two types: UAPs (client UAPs) which request services and UAPs (server UAPs) which provide services. A client UAP and a server UAP are required to implement one job.

A server UAP must be created only to provide services. The server UAP can be shared by multiple UAPs.

A client UAP can request a server UAP service by using a remote procedure call (RPC). The RPC allows the client UAP to request the server without recognizing the node at which the server UAP exists. Also, the UAPs do not have to consider the communication protocol between nodes.

For client/server mode communication under the OpenTP1, either TCP/IP or OSI TP can be used as the communication protocol. For either case, UAPs need not be aware of the internode communication protocol.

Node

In this manual, a node means a machine at which OpenTP1 connected to a network operates. When multi OpenTP1 is used, a node consists of more than one OpenTP1.

The figure below shows UAPs in client/server mode.

Figure 1-2 Outlines of UAPs in client/server mode