Annex B (informative) Use cases ToC Previous

B.8 Use case: Write device parameters ToC Previous Next

Use Case Writing Online Device Parameter  
Description The OPC client allows configuring or updating parameter values on the device. Writing is executed from an OPC client to an OPC server providing the FDT OPC UA information model.  
Preconditions Use Case B1 (List Topology)  
Post conditions OPC client can retrieve the updated device parameter values  
Actors Field Engineer, Device Expert, Maintenance Engineer  
Trigger Device Commissioning, Device Calibration, Device Configuration  
  Step Action
  2 User starts browse from Device Topology
  3 OPC Client displays the topology to the user
  4 User browse the parameters on the selected device
  5 OPC Client displays available parameters on the device
  6 User selects the device parameter that the value needs to be updated or changed
  7 User changes the value of the selected device parameter based on its type
  8 User commits the changes
  9 OPC server puts the lock on the device
  10 OPC server validates the specified parameter value
  11 OPC server writes the updated value to the device
  12 OPC server removes the lock on the device
  13 OPC client displays the new value of the selected device parameter
Exceptions Step 7, Value does not match the data type of the device parameter.  
  Step 8, Device is in locked state.  
  Step 10, Value exceeds the minimum and maximum limit specification of the device parameter.  
Requirements User has access permissions to the server  
Open Issues    

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