7/28/2010 3:52 PM | |
Posts: 16 Rating: (1) |
Dear Phantom Please see the extract form the documentation on CFC's Additional distinctions Blocks also differ in their type. When a block is created, it must be declared as a function block (FB), function (FC) or basic operation (BOP). ● The FB has a memory function. Existing data can be accessed across several processing cycles. Data access is enabled by creating a data block (DB) for each block instance. In a complex block, however, the FB contains additional subsidiary FBs, but only one common DB. ● The FC does not have a memory function. The values generated by the block are processed directly. No data block is required here. Outputs of an FC are not assigned default values. ● The BOP does not have a memory function, the same as the FC. Its basic operations form part of the CFC program and are entered as SCL statements during compilation and used for basic functions such as AND and OR. Attachments7cfcs7b.pdf (76 Downloads) |
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