Delivery state

General information on data consistency

The EJ6080 module can be used to cyclically store machine data in a fail-safe manner. A corresponding feedback in the status (cyclic operation) confirms that the data has been correctly transferred from the module. The data must appear correctly in the CoE in acyclic operation mode.

• It may happen that during a (a)cyclic write access by the task, the module is de-energized or the task is stopped.
• In the EJ6080 module, shadow buffers or the NOVRAM ensure data consistency at the lowest level for this case, so that the last correctly written data set can always be accessed.
• At the application layer, however, the user must ensure by appropriate application that the application adopts consistent data, e.g. at startup (e.g. continuous counters or ID identifiers in the data to be saved).
  
  Example:
  Several acyclic data objects 1 to 3 are defined, which are described continuously in sequence by the application (e.g. three axis positions determined at the same time in the application). The power fails during write access to object 2. Then object 1 contains the current axis position 1, but objects 2+3 contain obsolete ("Status" object 0xF100:01 = 0x0400 (Old Novram object restored). At restart, the application must not assume that it is receiving 3 axis positions originating from the same point in time.
• The same side effects must be taken into account in the case of simultaneous operation of the EtherCAT plug-in module EJ6080 and persistent/retain/other NOVRAM data (e.g. from FC cards or CX).

Readiness for operation of the EJ6080

• It is imperative that you ensure in your application that the module has a valid WorkingCounter WcState before beginning with writing and, in particular, reading communication!
• Process data delivered by an EtherCAT slave when the WcState is ≠ 0 (even if the data is ≠0) must be discarded as invalid!

CoE directory EJ6080

The functionality of the EJ6080 module results in CoE objects being deleted or created during reparameterization.

• Please refer to the notes in chapter Definition of the memory objects via the StartUp list in order to ensure correct online CoE display.