VIPA SSM-BG41 - Fig. 4-1: Evaluation Possibility 1 with the Help of Write and Read Pointers; Fig. 4-2: Evaluation Possibility 2 with the Help of Write and Read Pointers

Handling with VIPA data handling blocks Manual BG41/BG42/BG43
4-16 Rev. 99/49
Example 1: Write and read pointer
The read pointer is placed at the position of the write pointer, if the data received is processed by the
user program. If data is newly received after this, the write pointer is again increased by one for
every byte (calculated from the new starting point) and the read pointer is updated accordingly.
Fig. 4-1: Evaluation possibility 1 with the help of write and read pointers
Example 2: Write and read pointers
The second evaluation possibility is to always leave the read pointer at 0 and to reset the write
pointer to 0, if the received data is processed by the user program. The read pointer always points
directly to the number of bytes received.
Fig. 4-2: Evaluation possibility 2 with the help of write and read pointers