8.5
Handling the quality code of cyclic data
Quality code of cyclic data
During startup, the Compact FF Link initializes the I/O data for FF devices with "0" internally.
This action also sets the quality code to "Bad".
Once an FF device has been identified (correct name and address), its output data is
transferred from the DP master to the FOUNDATION Fieldbus and the input data from the FF
device to the DP master. (A special feature during the startup delay time is that the output data
continues to be kept at "0".)
Upon failure of an FF device, the I/O data and the quality code will be deleted (= "0").
On failure of the higher-level DP master (e.g. transition from RUN to STOP, DP cable
disconnected, CPU switched off), all output data and the quality code will be deleted (= "0").
During normal operation (CPU in RUN), the output data is transferred in a transparent
operation.
In normal operation, the input data is adapted (alignment with the PROFIBUS PA definition):
● Quality codes 0x84 ... 0x87 are mapped to: 0x80 ... 0x83
● Quality codes 0x90 ... 0x93 are mapped to: 0x80 ... 0x83
Operation of the bus link
8.5 Handling the quality code of cyclic data
Compact FF Link
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Operating Instructions, 03/2015, A5E35651552-AA