Principles of Operation

To enable the same user interface to be activated by users under different environments, a virtual environment is built for each user. This virtual environment handles all actions a user requests to perform in the IOA environment. Therefore, any environment being used at a site can be supported by adding a customized routine to convert the virtual environment to the site’s environment.

A special started task, named the IOA Online monitor (IOAOMON), provides an environment for executing IOA applications. One or more IOA Online monitors can be started and each monitor can support several virtual environments (signed‑on users).

Each monitor can customize INCONTROL product screens, constants, messages, colors, commands and PFKey definitions to adapt them to the site’s requirements. It is recommended that the same prefix be used for each group of monitors that are customized for specific functions. For more information, see the description of member IOAXPRM in the INCONTROL for z/OS Installation Guide: Installing.

In addition to site‑wide Global profile customization, each INCONTROL product can be customized to respond differently to individual users signed on to the IOA Online monitor through variables specified in User profiles.

In the CICS environment, a small conversational transaction communicates with the IOA Online monitor using cross‑memory services. The CICS transaction receives a screen from the user terminal and passes the screen to the IOA Online monitor for processing. The IOA Online monitor returns a screen (to be displayed) to the CICS transaction that in turn sends this screen to the CICS user at the terminal. Using this method, the IOA application is performed outside CICS and the normal CICS function is uninterrupted. The memory requirement of each user in the CICS region is approximately the size of the screen (that is, 2x24x80=3840 bytes).

The IOA Online monitor activates each user as a subtask. Therefore, in the event of an error or abend of a user application, other users working under the IOA Online monitor are not affected.

IOA applications work above and below the 16MB line. Therefore, region size limits may restrict the number of users who can work concurrently under the same online monitor. However, it is possible to open any number of additional IOA Online monitors. Each online monitor must have a different name. The general naming convention that is supplied is

x can be any valid job name character, a different one for each online monitor.

When a user enters the IOA CICS transaction code, the IOA CICS application searches for a free space in one of the currently active IOA Online monitors. The process of choosing a monitor is transparent to the CICS user. Using this method, there is no limitation on the number of users signing on to IOA.

It is possible to balance the workload of two or more IOA Online monitors. For more information see the BALANCE parameter in the IOA installation chapter of the INCONTROL for z/OS Installation Guide: Installing.

The actual number of users under one monitor varies according to their memory requirements (influenced by how many screens they use concurrently, what type of IOA options they are using, and so on). Many options exist in the IOA Primary Option menu. However, there is no reason for every user to access all options of each product. It may be desirable to limit access to certain options to only a selected group of users. This is done by passing a transaction code to the Online monitor. For more information, see Transaction Members. It is also possible to determine that certain monitors allow users to sign on only with specific transactions thus enabling monitors to be specialized for different groups and numbers of users.

The Control‑D Online Viewing facility runs mostly above the 16MB line. Therefore, it is possible to activate about 70 Online Viewing users under one monitor. However, these users are limited to Online Viewing transactions only. This can be done by forcing users to sign on with the transaction ID DOLV.

A data center can run more than one CICS in the same computer. From the IOA point of view, this is transparent to the user. The IOA Online monitor always returns the screen to the CICS that issued the request. It is possible to define additional transaction IDs for local use (for example, a transaction ID offering all options of the menu except for the IOA Conditions/Resources screen). For more information, see Customizing the IOA Online Environment.