20.6.8.4. CoSim

The CoSim block is for co-simulation between CoLink and User program. This block needs to use RecurDyn Solver with RecurDyn model.

20.6.8.4.1. CoSim Block

Dialog box

Table 20.66 Parameters
Parameter(s)	Description
Sampling Period (Control Time Step)	Enters the number of data from User program to CoLink.
Waiting Time (msec)	Waits the first communication with Simulink as inputted time. (Unit:MilliSecond).
Input (Colink =>Control SW)	Sets variables that define monitoring states from CoLink.
Output (Control SW=>Colink)	Sets variables that define actuator forces from control system design tools.

For the synchronous simulation of control design tool and RecurDyn, following four steps are required as shown in Figure 20.135.

RecurDyn/CoLink supports only User Program host mode. The user has to open the RecurDyn and Colink models.

Step I

Build or Open the RecurDyn model
- Any RecurDyn model can be used in this interface.
Build or Open the CoLink model
- Any CoLink Model can be used in this interface.
Make sure the CoLink model is correct.
- The CoLink model and RecurDyn model must be free of simulation errors. The modeling errors must be fixed in this step. If not, it is very difficult to modify the model in co-simulation.

Step II

In RecurDyn

Identify plant inputs.
- Define plant inputs and their variable names in the given list.
Identify plant outputs.
- Create the plant outputs and define them using the general expression function.

Step III

In CoLink

Identify inputs and outputs.
- Drag and Drop CoSim block in modeling window.
- Set variables as inputs and outputs.
- Connect input ports and output ports to other blocks with lines. The ports are created as much as variables.
Enter the Sampling Period and Waiting Time.

Step IV

In User Program

Library files: <Install Dir>\Toolkit\CoSim\CoSim_V8_Operator_DLL.lib, CoSim_V8_Operator_DLL.dll, CoSimGeneral.h

Interface Function

RunSimulation:

This function must be called only one before interfacing.

CommunicateRecurDyn:

This function must be called once at interface time step.

Table 20.67 Parameters
Parameter Name	Unit	Input/Output	Type	Description
sim_time	[ -]	Input	double	Is the simulation time
iNPin	[ -]	Input	int	Is the number of plant input
iNPout	[ -]	Input	int	Is the number of plant output
dPIN	[ -]	Input	double	Is the values of plant input
dPOUT	[ -]	Output	dou ble	Is the values of plant output
rd_time	[ -]	Output	double	Is the RecurDyn simulation time
error	[ -]	Output	int	0: no error 1: The model is abnormally stopped 2: The RecurDyn don’t respond. 3: Interface time don’t match.

GetStatusRecurDyn:

This function must be called once at interface time step.

Table 20.68 Parameters
Parameter Name	Unit	Input/Output	Type	Description
statusRD	[ -]	Output	Stat usRecurDyn*	Returns the number of plant inputs and plant outputs.
error	[ -]	Output	Int*	error>0 : no error

GetStringPlantInput:

Parameter Name	Unit	Input/Output	Type	Description
seq	[ -]	Output	int	Returns the sequence of plant input.
seq_input	[ -]	Output	char*	Returns the string of plant input defined the seq.
error	[ -]	Output	int*	error>0 : fails to return.

GetStringPlantOutput:

Parameter Name	Unit	Input/Output	Type	Description
seq	[ -]	Output	int	Returns the sequence of plant output.
seq_output	[ -]	Output	char*	Returns the string of plant output defined the seq.
error	[ -]	Output	int*	error>0 : fails to return.

CloseRecurDyn();

This function must be called only one after interfacing.

StopRecurDyn();

This function must be called only one after interfacing.

Step V

In User Program

Co-Simulation