Separating input and output devices

In certain application programs, it might be necessary to associate a different physical device for output than the one that is used for input. If the physical terminal type is an input-only device and output is required, a different device must be associated for output.

IMS system definition and commands support assignment of output devices that are different from the input device. For example, the application program that is processing a message from a display might need to send some of the output to a printer. The possible physical-to-logical relationships are shown in the following figure.

Figure 1. Possible physical-to-logical terminal relationships
Begin figure description: This figure is explained in the notes that follow. End figure description.

Notes to figure regarding applications

  1. Normal assignment of one or more logical terminals or physical terminals. Output is sent to input terminal. Application is insensitive.
  2. Application uses specific logical terminal for output. Application is insensitive to input.