DDS for display files

Conditioning for display files (positions 7 through 16)

Positions 7 through 16 are a multiple field area in which you can specify option indicators. Option indicators are 2-digit numbers from 01 to 99. Your program can set option indicators on (hex F1) or off (hex F0) to select a field or keyword. You can use option indicators to select fields to display different data on different output operations instead of defining a different record format for each combination of fields.

A condition is an ANDed grouping of two through nine indicators that must all be in effect (set off if N is specified; set on if N is not specified) before the field or keyword is selected. You can specify a maximum of nine indicators for each condition and nine conditions for each field or keyword. Therefore, a maximum of 81 indicators can be specified for each field or keyword. An AND condition occurs when you specify a condition requiring that more than one indicator must be on or off before the condition is satisfied. The first indicator you specify, AND the second, AND the third, and so on, must all be in effect before the condition is satisfied and the field or the keyword is selected. You must specify the field or the keyword on the same line as the last (or only) set of indicators specified.

You can also specify several conditions for a field or keyword so that if any one of them is satisfied, the field or the keyword is selected. This is called an OR relationship. In an OR relationship, if the first condition is satisfied, OR the second condition, OR the third condition, and so on, the field or the keyword is selected. Conditions within the OR relationship can consist of just one indicator or can consist of several indicators ANDed together. Indicators can be ANDed to form a condition. Conditions can be ORed to give your program several ways to select the field or keyword.

Position 7 (AND)
If you need more than three indicators to form an ANDed condition, specify the indicators on the next line or lines. You can specify an A in position 7 on the second or following lines to continue the ANDed condition, or you can leave it blank because A is the default.

Position 7 (OR)
If you specify several conditions that are to be ORed together, each condition must start on a new line and each condition, except the first, must have an O in position 7. An O specified for the first condition produces a warning message, and that position is assumed to be blank.

Position 8, 11, 14 (NOT)
If you want an indicator to be off instead of on to satisfy a condition, specify an N in the position just preceding the indicator (position 8, 11, or 14).


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