4.5.7 Interface IFdtFunctionBlockData

Available since FDT 1.2.0.0

Mandatory for:
Never implemented by:

This interface must be supported by DTMs for failsafe devices The root communication component of an FDT system defines whether the system can provide failsafe access or not. In a system that is able to provide failsafe access, it is important that all communication components support failsafe access. Communication channels have to support the propagation of the failsafe function calls. That is why the interface is mandatory for all channels with communication functionality. If the represented gateway device does not provide failsafe functionality itself, it is sufficient to pass the function call to the underlying communication. Gateway-DTMs and Device-DTMs have to be aware that the underlying communication might not support the interface. The interface is part of the communication channel of a bus-master-DTM to allow an extendable topology. The DTM that manages the failsafe function blocks (FB) would be part of the Frame Application and would be DCS specific. Communication channels have to do the propagation of the failsafe function calls. That is why this interface is mandatory for all channels with gateway functionality. The interface to the bus master comprises two calls. The first one causes the Frame Application to open up a browser displaying the failsafe host and the available device function blocks. The user may select one that will be associated (assigned) with the DTM. The second call provides the individual device parameter block packed within an XML frame. The XML frame provides information about the bus master and the device FB.