M&M FDT 1.2.1 Online Specification
 6.27 Instantiation of DTM and BTM


Interfaces and Methods   -   Schemas   -   FDT Specification   -   Quicklinks   -   Abbreviations

Up to FDT Specification

6.1 DTM Peer To Peer Communication
6.1.1 Establish a Connection between DTM and Device
6.1.2 Asynchronous Connect
6.1.3 Asynchronous Disconnect
6.1.4 Asynchronous Transaction
6.2 Nested Communication
6.2.1 Generate Systemtopology
6.2.2 Establish a Connection between DTM and Device
6.2.3 Asynchronous Transaction
6.3 Topology Scan
6.3.1 Scan Network
6.3.2 Cancel Topology Scan
6.3.3 Provisional Scan Result Notifications
6.3.4 Scan for Communication Hardware
6.3.5 Manufacturer specific Device Identification
6.4 Registration of Protocol Specific FDT Schemas
6.5 Configuration of a Fieldbus Master
6.6 Starting and Releasing Applications
6.7 Channel Access
6.8 DCS Channel Assignment
6.9 Printing of DTM Specific Documents
6.10 Printing of Frame Application Specific Documents
6.11 Propagation of Changes
6.12 Locking
6.12.1 Locking for Non Synchronized DTMs
6.12.2 Locking for Synchronized DTMs
6.13 Instantiation and Release
6.13.1 Instantiation of a New DTM
6.13.2 Instantiation of an Existing DTM
6.13.3 Instantiation of a DTM User Interface
6.13.4 Release of a DTM User Interface
6.14 Persistent Storage of a DTM
6.14.1 State machine of instance data
6.14.1.1 Modifications
6.14.1.2 Persistence
6.14.2 Saving Instance Data of a DTM
6.14.3 Reload of a DTM Object for Another Instance
6.14.4 Copy and Versioning of a DTM Instance
6.15 Audit Trail
6.16 Comparison of Two Instance Data Sets
6.16.1 Comparison Without User Interface
6.16.2 Comparison With User Interface
6.17 Failsafe Data Access
6.18 Set or Modify Device Address With User Interface
6.19 Sets or Modifies Known Device Addresses Without User Interface
6.20 Display or Modify All Child Device Addresses With User Interface
6.21 Device Initiated Data Transfer
6.22 Starting and Releasing DTM User Interface in Modal Dialog
6.23 Parent Component Handling Redundant Slave
6.24 Initialization of a Channel ActiveX Control
6.24.1 Supports IFdtChannelActiveXControl2
6.24.2 Does Not Support IFdtChannelActiveXControl2
6.25 DTM Upgrade
6.25.1 Saving Data from a DTM to be Upgraded
6.25.2 Loading Data in the Replacement DTM
6.26 Usage of IDtmSingleDeviceDataAccess::ReadRequest / Write Request
6.27 Instantiation of DTM and BTM

6.27 Instantiation of DTM and BTM

A BTM is created by the same mechanism as a DTM, which means the Frame Application always creates a BTM. If a DTM must create a BTM, it has to use the interface IFdtTopology of the Frame Application. BTMs are instantiated by:
  • Frame Application according to the defined sequence defined
  • DTM triggers as described below.
The word defined is duplicate here.
The verification of assigned Child-BTMs is done by using the ValidateAddChild() method of the IFdtChannelSubTopology interface. The general sequence is shown in the following chart. The creation of BTMs is possible in any of the following states:
  • Running
  • Configured
  • Communication set
  • Going Online
  • Going Offline
  • Online.
The trigger for creating BTMs (shown in the chart by the event "Trigger to Initiate BTMs") can originate from the following sources:
  • The DTM GUI (e.g. the GUI of the running DTM provides a method "Add block")
  • A function exposed by the DTM (that is, a function without GUI)
  • An event on the DTM (e.g., transition from state "Running" to state "Configured")

In contrast to other sequence charts, this one seems to consider time, except for the creation of channels.
What does *: mean?
The Frame Application can reject the CreateChild() method. In this case, the procedure of creation of the BTM is aborted. It is up to the user to create the BTM. It does not matter how to trigger BTMs initiation. The general sequence of events does not change. Thus, each DTM and each BTM is handled according to the DTM State Machine. If the DTM is loaded (transition from Up to Existing Created to Running states), it shall not automatically trigger the BTM creation. The Frame Application should handle the instantiation of the BTMs.
© by M&M Software GmbH, parts of this website taken from FDT Interface Specification Version 1.2.1, © by FDT Group, AISBL.
This website is published for support of M&M products as granted in license conditions, chapter 2.1.
Last updated 2015-02-05 15:17
Email: FDT Technical Support Line.