Ph.D. - geht es zur Homepage der Informatik des Fachbereiches 3 ...

8.5. Deployment Design
8.5. Deployment Design
The deployment design describes how the source code and the compiled binary code is distributed
on different platforms for their execution. For openETCS and its domain framework, this is
of special interest regarding the separation of platform-specific adaptations from the directly
generated code by hardware virtualisation, which was discussed in Chapter 6.
For clarification, the openETCS architecture is divided in three categories:
Computational Independent Model (CIM) is the part of the DSL that does not hold any
certain information about computation structure and processing of the system [44, p. 2-5].
This corresponds to the openETCS model.
Platform independent model (PIM) provides information about computational and processing
structure of the system without any information depending on a certain target
platform [44, p. 2-6]. This corresponds to the openETCS domain framework (see Req.7)
and the code generated from the openETCS model / CIM.
Platform specific model (PSM) extends the PIM or is a transformation of it to be applicable
on a certain platform [44, p. 2-6]. In the openETCS architecture, this corresponds to
possible adaptations for concrete hardware devices, like sensors and actuators (Section 7.2).
While CIM and PIM are already defined for the openETCS case study, the PSM is defined
in the deployment. Due to the fact that this work primary focusses on the CIM and PIM,
platform-specific adaptations are only used for testing and simulation purposes. Nevertheless,
the deployment design should provide a general approach for extending the PIM about PSM
elements of any kind. Figure 8.14 introduces the deployment of the openETCS domain
framework with the separation of PIM and PSM as UML deployment diagram [64]. Both are
located on the target platform, the EVC, but are executed in separated execution environments.
Both execution environments can communicate (over a network link) with the EVC but not
directly with each other. Communication between them is only possible via the EVC, on which
this communication could be limited by a firewall or other mechanisms.
All source artefacts located in the PIM execution environment manifest together the libopen-
ETCSPIM component, which is a library. This library represents the platform independent
implementation (parts) of the openETCS domain framework. On the other hand, the libopen-
ETCSPSM is the manifestation of the platform specific implementation base within the PSM
execution environment. Each source artefact is shortly explained in the following:
EVCStateMachine
ControlFlow
FunctionBlocks
Language
Holds all source code that is basically needed by the CEVC-
StateMachine class. This includes all required types for data
flows.
All sources for control flows, including CControlFlow and
CState.
Sources of all platform independent function block classes.
Includes all sources for the ETCS language classes.
141