Technical data

12.1 Use and Types of FMA Service
The fieldbus management (FMA) organizes the initialization, monitoring and
error handling between the FMA user and the logical functions in layers 1
and 2.
The management therefore serves as mediator between the local user and
layers 1 and 2. Service requests which may be specified by the
management are passed on to layers 1 or 2 and the user of the FMA
services receives an acknowledgement with a confirmation.
The FMA services permitted for the SINEC L2 bus system allow diagnosis
of all the systems belonging to the bus and their links.
When using the FMA services and the clock function at the same time, the
following feature of the CP must be noted:
☞
If the CP is the clock master on the L2 bus and if an FMA
service is triggered at the same time, this can lead to delays
in the transmission of the cyclic time of day frame.
Service and Diagnostics using FMA Functions B8976060/02
Volume 1 12 - 2