Operation of the bus link
8
8.1
Startup/operation without CPU
Introduction
You can download the FF bus parameters and LAS data (scheduler) to the bus link and the
FF devices using
HW Config or SIMATIC PDM. The data is stored retentively there. Because
the FF parameter assignment is stored retentively in the Compact FF Link and the FF devices,
the FOUNDATION Fieldbus starts up automatically after Power ON.
Requirements
All FF devices are configured and the FF bus is switched on and controlled by the active
Compact FF Link (with CiF, if applicable).
Startup scenarios without CPU
During startup without CPU, only acyclic communication with the FF devices is possible via
SIMATIC PDM that is connected directly to PROFIBUS DP, e.g. for commissioning. The
following cases are distinguished:
● FF bus parameters are missing
– FOUNDATION Fieldbus starts up with default bus parameters
● FF bus parameters present, LAS data (scheduler) is missing
– FOUNDATION Fieldbus starts up with the specified bus parameters
● FF bus parameters and LAS data (schedule) present
– If the FF devices have not received their configuration, the FOUNDATION Fieldbus
starts up with its cyclic communication. However, there is no process image update or
communication among the FF devices.
– If all FF devices have received their configuration, the FOUNDATION Fieldbus starts
up with its cyclic communication. However, there is no process image update. Output
data from the Compact FF Link is set to "0". CiF is functioning.
Compact FF Link
Operating Instructions, 03/2015, A5E35651552-AA
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