Troubleshooting issues with Rhapsody PCE and Matlab

Troubleshooting

Problem

Here are some ways you can troubleshoot the integration between the IBM Rhapsody® PCE add-on and Mathworks® MATLAB.

Environment

When you right click a Constraint View and select "Open Contraint View...", Rhapsody® launches a plugin helper that opens a UI.

The plugin also opens an instance of MATLAB® and connects to the instance via a HTTP socket. The plugin will attempt to find the socket defined by MATLAB. If not it defaults to 6434.

When the user presses the "Evaluate" button in the UI, the Rhapsody® plugin executes the MATLAB® scripts located in the PCE profile directory (shown below)

These MATLAB® scripts then call more Rhapsody API code in order to evaluate your model's parametric constraints in MATLAB®.

You can modify these MATLAB® scripts to obtain further debug information.

Resolving The Problem

1. Check you have a valid path for the MATLAB® executable path in the the Rhapsody® tools menu > PCE Enviroment Settings.

2. Check MATLAB® has exported the MATLAB_PORT_NO environment variable. This is used by the Rhapsody® plugin to connect to launch an instance of MATLAB®. Test it by running this from the MATLAB® console:

disp(getenv('MATLAB_PORT_NO'));

MATLAB® should print the port number on the console.

3. Check the Rhapsody plugin has connected successfully to the MATLAB® instance by modifying the xpceMATLAB.m script:

xpceServer = com.ibm.rhapsody.pce.net.Server();

// add this line
disp(xpceServer.COPY_RIGHT);

This will output the copyright banner into the MATLAB® console if successfully connected.

4. Increase the level of detail from error messages in the MATLAB® console. Open the xpceMATLABexecute.m script.

In each catch section add further disp() functions to output exception details. A modified example is shown below:

%
% MATLAB script for Rhapsody Parametric Constraints Evaluator
% xpceMATLABexecute.m
%
% (C) Copyright IBM Corp. 2010. All rights reserved.
%

while true
	xpceRequest = xpceServer.receiveRequest();
	if (length(xpceRequest) <= 0)
		break
	elseif xpceRequest == 'xpceQuit'
		xpceServer.finalizeServer();
		quit
	elseif xpceRequest.endsWith(';')
		try
			eval(xpceRequest);
		catch ME
			disp('    => eval error!')

			// output additional exception info
			disp(ME.identifier);	
			disp(ME.message);
			disp(ME.stack);
			disp(ME.cause);							
			//
			
		end
	elseif xpceRequest.endsWith(':')
		try
			evalin(symengine,char(xpceRequest));
		catch ME
			disp('    => evalin error!')

			// output additional exception info
			disp(ME.identifier);	
			disp(ME.message);
			disp(ME.stack);
			disp(ME.cause);							
			//			
		end
	else
		try
			xpceAnswer = eval(xpceRequest);
			if (isnumeric(xpceAnswer) | islogical(xpceAnswer))
				xpceServer.sendResult(num2str(xpceAnswer));
			else
				xpceServer.sendResult(char(xpceAnswer));
			end
		catch ME
			xpceServer.sendResult('');
			disp('    => eval error!')

			// output additional exception info
			disp(ME.identifier);	
			disp(ME.message);
			disp(ME.stack);
			disp(ME.cause);							
			//
		end
	end
end

Now when you press the "Evaluate" button again, you should receive more logging information in the MATLAB® console:

If you receive errors such as:

MATLAB:UndefinedFunction
Unrecognized function or variable 'symengine'.

MATLAB:UndefinedFunction
Undefined function 'syms' for input arguments of type 'char'.

MATLAB:UndefinedFunction
Unrecognized function or variable 'x0'.

Type 'symengine' in the MATLAB console.

If it is missing, click the red link to purchase and/or download the missing package.

Further errors displayed on the console should be forwarded to IBM Support.

Document Location

Worldwide

[{"Type":"SW","Line of Business":{"code":"LOB59","label":"Sustainability Software"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSB2MU","label":"IBM Engineering Systems Design Rhapsody"},"ARM Category":[{"code":"a8m50000000CjWPAA0","label":"Rhapsody->Collaborations->Simulink"}],"ARM Case Number":"TS005569913","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Version(s)"}]

Tips

Troubleshooting issues with Rhapsody PCE and Matlab