External link

External .dll communication interface.

Collaboration diagram for External link:

Special class of SimObject that can have it's ports read and set from outside the simulation. This implements the interface in ExternalLink

Author

Jorgen Haavind Jensen

Date

16.02.2011 JHJ: Initial version.

Configuration parameters

See example file at the bottom of this page, for clarification.

Name	Width	Description
outputPortNames	n	Comma separated list of output port names.
Initial_<outputPortName1>...Initial_<outputPortName<n>>	m	One for each output port name. Initial values for each output port.
inputPortNames	k	Comma separated list of input port names.
Size_<inputPortName1>...Size_<inputPortName<k>>	1	One for each input port name. Size of each input port.
Initial_<inputPortName1>...Size_<inputPortName<k>>	size_<inputPortName<..>	One for each input port name. Initial values for each input port.

Note

In/Out-put ports can be referenced both as their name and number. The number corresponds to the index in the respective vectors from GetAllInputPorts()/GetAllOutputPorts().

There are two different ways of setting the output port values of an ExternalLink. With and without copy. Without-Copy only stores the given memory reference. Other processes that have access to the same memory reference can change values of the port at any time. With-Copy transfers the data from the given memory reference to a local buffer.

The internal state and time must be updated with "UpdateStatesAndTime" before correct values can be retrieved from the "GetMyInputPort" functions.

Full example file

<Contents>
  <OBJECTS>
    
    <Lib
        LibName="base" 
        SimObject="System/ExternalLinkStandard"  
        Name="ExtLink" 
        outputPortNames="out1"
        Initial_out1="0,0,1"
        inputPortNames="in1"
        Size_in1="3"
        Initial_in1="2,2,2"
    />
    
    <Lib
        LibName="base" 
        SimObject="Body/Mass"  
        Name="M" 
        Scale="1"
        Mass="1"
    />
 
  </OBJECTS>
  
  <INTERCONNECTIONS>
    <Connection
        ExtLink.in1="M.Pos"
        M.Force="ExtLink.out1"
    />
  </INTERCONNECTIONS>
 
  <INITIALIZATION>
    <InitialCondition
        M.Pos="1,1,1"
        M.Vel="0,0,0"
    />
  </INITIALIZATION>
 
  <SIMULATION>
    <Timing TStart="0" TEnd="11.0"/>
    <Integrator Method="RK45_i" NumCores="1" LogStates="1" UseRSSNorm="0">
      <StepControl StepMax="0.002" StepMin="0.00000001" AbsTol="1e-3" RelTol="1e-3"/>
    </Integrator>
    
  </SIMULATION>
 
<OBSERVERS>
    <FileOutput TOutput="0, 0,1,2, 30" Select="objects:all"/>
  </OBSERVERS>
</Contents>

This SimObject is referred to as ExternalLinkStandard

This SimObject is referred to as System/ExternalLinkStandard