{"id":170,"date":"2011-12-05T20:00:39","date_gmt":"2011-12-05T20:00:39","guid":{"rendered":"https:\/\/blogs.mathworks.com\/seth\/?p=170"},"modified":"2011-12-06T08:49:22","modified_gmt":"2011-12-06T13:49:22","slug":"initializing-buses-using-a-matlab-structure","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/simulink\/2011\/12\/05\/initializing-buses-using-a-matlab-structure\/","title":{"rendered":"Initializing buses using a MATLAB Structure"},"content":{"rendered":"

Did you notice that since R2010a it is possible to initialize buses with a MATLAB structure? If you were not aware, here is how it works.<\/p>\r\n\r\n

Starting from a Structure<\/strong><\/p>\r\n\r\n

Let's say I have a structure in the MATLAB workspace and I would like to make that a bus signal in Simulink. I can use Simulink.Bus.createObject<\/a> to create a bus object<\/a>:<\/p>\r\n\r\n\r\nmyStruct.a = 5;
\r\nmyStruct.b = true;
\r\nmyStruct.c.x1 = 22;
\r\nmyStruct.c.x2 = 3;
\r\nbusInfo = Simulink.Bus.createObject(myStruct);
\r\n<\/code>\r\n\r\n

Then I can configure a Constant<\/a> block to use this bus object as data type and to use myStruct<\/tt> as value.<\/p>\r\n\r\n

\"Configuring<\/p>\r\n\r\n

\"Constant<\/p>\r\n\r\n

Starting from a model<\/strong><\/p>\r\n\r\n

Let's say I have the following model where a bus signal is going through a Unit Delay<\/a> block. I want to specify different initial values for the elements of the bus.<\/p>\r\n\r\n

\"Specifying<\/p>\r\n\r\n

In that case I can use the handle to a port of the Unit Delay block as input to Simulink.Bus.createMATLABStruct<\/a>. This will create a MATLAB structure with the same hierarchy as the bus, filled with zeros. I can then overwrite fields of this structure as needed and use it as the initial value of the Unit Delay.<\/p>\r\n\r\n\r\nportHandle = get_param(gcb,'PortHandles');
\r\ninitStruct = Simulink.Bus.createMATLABStruct(portHandle.Inport);
\r\ninitStruct.bus2.Pulse = 5;
\r\ninitStruct.signal1.Chirp = 3;
\r\n<\/code>\r\n\r\n

Requirements to Use Bus Signal Initialization<\/strong><\/p>\r\n\r\n

To enable bus signal initialization, you need to set two Configuration Parameter diagnostics:\r\n