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Appendix A.6. Rules for Naming Logix driver Data Arrays
Unlike most other FieldServer drivers, the Logix driver attaches significance to the name of the Data Array used in the Logix Driver Map Descriptor. This is done to allow the user to easily declare a series of Data Arrays to be multiplexed through the input and output buffers of the SlotServer. Most users will probably stick to a naming convention where the Data Arrays are named In_1 to In_x for input buffer arrays, and Out_1 to Out_y for output buffer arrays (where x and y are numbers reflecting the maximum input and output Array numbers respectively).
For example, an application that multiplexes 6 Data Arrays worth of data through the Input buffer will probably use data arrays named In_1 though In_6. In this example, DA_Name_Start is declared as In_1, and DA_Count is declared as 6.
It is not absolutely necessary to use the naming convention described above, however, and while the user has some latitude for declaring names, the following restrictions must be understood before attempting a different naming convention:
•The Data Array name must end in _x, where x is a positive integer number.
•The total length of the Data Array name (including _x) must not exceed 15 characters.
•No leading zeros should be used in the _x number (For example, use _5, not _05)
•The “x” part of the _x in the data array name will be the number shown in offset 2 of the input buffer for the purposes of
•There can only be one Map Descriptor for linking Data Arrays to the input buffer, and one Map Descriptor for linking Data Arrays to the output buffer (Using wrbc in the function parameter links the Map description to the input buffer, and using rdbc links the map description to the output buffer). This means that trying to map Data Array number sequences that are not continuous will not be possible (For example, you can map numbers 5 through 25, but you cannot map numbers 1 through 3, and then 5 through 8 at the same time).
•The Data Arrays must be declared individually in the Data Arrays Section. Declare all data arrays, not just the start Data Array.
The following examples describe legal and illegal naming conventions respectively:
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