Terminal Management › Mapping Mode

Mapping Mode

In mapping mode, your program communicates with 3270-type terminal devices. DC uses maps to associate screen positions on the terminal with fields in program variable storage.

Example of Map Data Fields

The EMPDISPM map below associates row 4, column 24, with the EMP-ID-0415 field in variable storage; the map associates row 5, column 24, with the EMP-LAST-NAME-0415 field, and so on.

                   *** EMPLOYEE INFORMATION SCREEN ***

               EMPLOYEE ID : ____
                 LAST NAME : ____________
                FIRST NAME : ________________
                   ADDRESS : ________________
                           : ____________
                           : __ __________

                DEPARTMENT : ____________________








    ENTER AN EMPLOYEE ID AND PRESS ENTER  ***  PRESS CLEAR TO EXIT

Creating a Map

To transfer data in mapping mode, you must first create a map by using either the online or batch compiler of the CA IDMS Mapping Facility. You associate map variable fields with either database records or IDD-defined work records.

Maps are available as load modules to the DC run-time system. DC views map load modules as programs.

Mapping Mode Terminal Management

Using mapping mode terminal management, you can perform the following functions:

• Write data to a terminal screen
• Read data input from a terminal screen and query the status of conditions related to the input operation
• Modify previously established map and map field options
• Write unlimited detail occurrences that can be displayed one page at a time by using a pageable map

Mapping Terminology

You should understand the following terms related to maps:

• Attribute byte-The nondisplayable byte that begins each map field at run time. The contents of the attribute byte determine the characteristics of the field (such as protection and intensity). Attributes bytes are a 3270 feature.
• Automatic editing and error handling-An optional map feature that can be used to perform editing and error-handling functions at run time. These functions can compare input and output data with internal and external pictures, validate data against edit tables, and encode or decode data through code tables.
• Modified data tag (MDT)-:ih1.modified data tag The internal switch for a map data field that indicates whether the value in that field has been changed by the user. Modified data tags are a 3270 feature.
• Write control character (WCC)-The internal character that holds various specifications for the display of the map such as resetting the keyboard to allow user input. Write control characters are a 3270 feature.

For a complete description of maps and map attributes, see CA IDMS Mapping Facility Guide.