Static Database Fields
Because of the large amount of information involved, the static database field pages are broken up into the following related sets:
The tables documenting the database fields are currently designed from a programmer's perspective, referencing actual structure and member names used in writing code to access the tables. The column headings are:
- Member Name
- Name of the C language field (within the data structure). EVI's coding style guidelines require a prefix (related to the structure name) an underscore and a descriptive name. Unfortunately, in some cases a field has been overloaded with multiple meanings (typically for different point data types) as development progressed.
- Key
- Key fields have a "Yes" or "Unique" here, where "Unique" means that there can not be two records with this same key value in the table. "Yes" allows duplicates to exists in the database for this field in this table. Key fields are used to set the effective sort order of the database for first/next/previous access operations or for efficient direct access by key value.
- Range
- The range gives the acceptable values for a field. For numeric fields this is normally a numeric range such as 1 - 63. Numeric fields used as bit fields may refer to table in their descritptions. For character fields this will experess the type of charater strings such as "Pointname Characters".
- Type
- Type is the C-language data type of the field content. The basic data types are shown in the table below. Fields that are an array of the type have their dimension shown as a value in parenthesis after the basic type.
| BYTE |
unsigned 8 bit binary value |
| CHAR |
single ASCII character (typically an array of these) |
| SHORT |
signed 16 bit binary value |
| WORD |
unsigned 16 bit binary value |
| DWORD |
unsigned 32 bit binary value |
| FLOAT |
IEEE single-precision floating-point binary value |
| DOUBLE |
IEEE double-precision floating-point binary value |
- Description
- Textual description of the field content.
