Determine Whether to Specify Reference Block

To take programmatic action using a function, read the function documentation and determine what type of target object you can specify in the input arguments. If the function can only act on models, libraries, subsystems, or a subset of these, or if the function can only act on blocks, you know what to specify. Otherwise, use the interactive approach to the workflow as a guide.

When you edit a model, library, or subsystem interactively, you can take some actions on the component by opening the component and interacting with the contents. To make the same edits programmatically, specify the component. You can take other actions by interacting with blocks that reference the component. To take the same actions programmatically, specify the block.

For example, suppose you have a subsystem that is saved to a subsystem file named mySubsystem. You also have a model named myModel containing a Subsystem Reference block named mySubsystemRefBlock that references the subsystem. To change the canvas color of the subsystem, use the set_param function. In the function input arguments, specify the subsystem.

set_param("mySubsystem","ScreenColor","green")

To see the change in the model, you must update the model diagram. To programmatically update the diagram, use the set_param function. In the function input arguments, specify the model.

set_param("myModel","SimulationCommand","Update")

To treat the subsystem as atomic, use the set_param function. In the function input arguments, specify the Subsystem Reference block.

set_param("myModel/mySubsystemRefBlock",TreatAsAtomicUnit="on")

To get a list of the parameters that you can get and set programmatically when you specify a model, first, load the model by entering this command in the MATLAB Command Window. myModel is the model filename.

load_system("myModel")

Then, enter this command.

get_param("myModel","ObjectParameters")

To get a list of the parameters that you can get and set programmatically when you specify a block, load the model containing the block. Then, enter these commands. path is the block path.

param = get_param(path,"ObjectParameters");
param = fieldnames(param)

The list of parameters output by these commands does not include the mask parameters you can get and set on a masked block when you specify the block. To get a list of the mask parameters, enter these additional commands.

paramMaskStruct = get_param(path,"DialogParameters");
paramMask = fieldnames(paramMaskStruct)

If you determine that you need to specify a model, library, or subsystem, see the next section. If you determine that you need to specify a reference block, see Specify Block.

Specify Model, Library, Subsystem, or Current System

To programmatically specify a model, library, or subsystem, use a handle or filename. For example, to set the solver of a model named myModel with the handle h to ode45, use one of the commands in the Example column of the table.

set_param(h,SolverName="ode45")

set_param("myModel",SolverName="ode45")

To specify the current system, use the handle or filename of the current system. For the definition of the current system, see gcs. To get the model that contains the current system, use the bdroot function.

path = gcs

h = get_param(gcs,"Handle")

If a file is not in the current folder or on the MATLAB search path, using the filename to specify the model, library, or subsystem the file contains is not supported. In this case, take one of these actions.

Get Model, Subsystem, or Library Handle

You can programmatically get the handle of a loaded model, library, or subsystem, you can get the handle of a model, library, or subsystem while taking certain actions, and you can get the handle of the harness model for a protected model.

To get the handle of a loaded model, library, or subsystem, use this command.

h = get_param("myModel","Handle")

The table shows how you can get the handle of a model, library, or subsystem while taking an action. Use the function documentation to select a syntax that outputs the model, library, or subsystem handle.

h = new_system("myModel")

h = Simulink.createFromTemplate("myTemplate")

h = load_system("myModel")

h = find_system("myModel",FindAll="on")

h = Simulink.allBlockDiagrams("model")

To get the handles of multiple models, libraries, or subsystems at once using the load_system, get_param, new_system, or find_system function, specify the model filenames as one of these.

models = ["myModel1";"myModel2";"myModel3"];
h = get_param(models,"Handle")

models = {'myModel1';'myModel2';'myModel3'};
h = get_param(models,"Handle")

To get the handle of the harness model for a protected model, use the Simulink.ModelReference.protect (Embedded Coder) function.

h = Simulink.ModelReference.protect("myModel",Harness=true)

Get Block Path

The block path specifies the location of the block relative to the top level of the model. Generally, the path starts with the model name and ends with the block name, for example, myModel/mySubsystem/myBlock.

If the block is in a referenced model, the block path is the path from the top level of the referenced model to the block. To take inventory of blocks in referenced models, get the Simulink.BlockPath objects corresponding to the blocks . A Simulink.BlockPath object uniquely identifies a block within a model hierarchy, even when the model hierarchy references the same model multiple times. If you do not have a Simulink license, use a Simulink.SimulationData.BlockPath object instead.

To get the path of a Library Browser block:

Get Block Handle

You can programmatically get a block handle from a block path, you can get a block handle while taking certain actions, and you can get the handle of the block that a specific port is on or to which a specific signal line connects.

To get a block handle from a block path and load the model with one command, use the getSimulinkBlockHandle function with this syntax. path is the block path, specified as a string or character vector.

h = getSimulinkBlockHandle(path,true)

To get the handle of a block in a loaded model, use this syntax.

h = getSimulinkBlockHandle(path)

To get the handles of multiple blocks at once using the getSimulinkBlockHandle function, specify the block paths as a cell array of character vectors.

paths = {'myModel/myBlock1';'myModel/myBlock2';'myModel/myBlock3'};
h = getSimulinkBlockHandle(paths)

The table shows how you can get the handle of a block while taking an action. Use the function documentation to select a syntax that outputs the block handle.

h = add_block("simulink/Sinks/Scope","myModel/myBlock")

h = find_system("myModel",FindAll="on",Type="block")

hModel = get_param("myModel","Handle");
h = Simulink.findBlocks(hModel)

h = Simulink.findBlocksOfType("myModel","Integrator")

path = replace_block("myModel","Scope","simulink/Sinks/To Workspace")
h = getSimulinkBlockHandle(path)

connection = simulink.connectBlocks(hSrcPort,hDstPort);
transits = connection.getTransits;

hFunc1 = @(t) transits(t).getType=="block";
hFunc2 = @(t) transits(t).getHandle;
i = 1:numel(transits);
isTypeBlock = arrayfun(hFunc1,i);
h = arrayfun(hFunc2,i);
h = h(isTypeBlock==1)

To get the handle and path of the block that a port is on, use these commands. hPort is the port handle. To get the handles and paths of the blocks for multiple ports at once, specify hPort as a vector of port handles.

path = get_param(hPort,"Parent")
h = getSimulinkBlockHandle(path)

To get the handles of the source and destination blocks of a signal line, use these commands. hLine is the line handle. If hLine represents the trunk of a branched signal line, the output is the destination blocks of all branches. If hLine represents one branch of a branched signal line, the output is the destination block of that branch. To get the handles of the source and destination blocks of multiple signal lines at once, specify hLine as a vector of line handles.

hSrc = get_param(hLine,"SrcBlockHandle")
hDst = get_param(hLine,"DstBlockHandle")

Get Port Path

The port path specifies the location of the port relative to the top level of the model. Generally, the path starts with the model name and ends with the port number, for example, myModel/myBlock/1.

To get the port number interactively, in the model, pause your pointer on the port. The port number appears in the canvas next to the port. To get the port number of a component block, such as a Subsystem or Model block, enter the component and pause your pointer on the block corresponding to the port, for example an In1 block. If you have a port handle, h, you can get the port number programmatically using this command.

portNum = get_param(h,"PortNumber")

There are some exceptions to the described path format.

One exception pertains to conditionally executed subsystems. The path that specifies the control input port on a conditionally executed subsystem starts with the model name and ends with the port name, for example, myModel/Triggered Subsystem/Trigger. The table lists the names of the control input ports for different types of conditionally executed subsystems.

Another exception pertains to buses. Suppose you want to query or edit the attribute value of a bus or bus element at a bus element port. For example, suppose you want to get or set the minimum value of a bus element at the point where the bus enters a subsystem. Use the get_param or set_param function. In the input arguments, specify the bus or bus element at the bus element port using a path.

If the In Bus Element or Out Bus Element block corresponding to the bus element port is at the top level of a model, start the path with the model filename. If the block is at the top level of a subsystem, start with the block path. To query or edit the attribute value of a bus, append a forward slash and the port name to the end of the path. To query or edit the attribute value of a bus element, append a forward slash and the bus element path. For a bus element port, the bus element path provides the hierarchy from the top-level bus to the target element, separating each name in the hierarchy with a dot. Specify the top-level bus using the port name.

For example, suppose you have a model named myModel. The model contains a Subsystem block named mySubsystem. The Subsystem block has a port named InBus. Inside the subsystem is an In Bus Element block named myBlock. The In Bus Element block selects the bus element named Step from the bus connected to the port named InBus. This path specifies the bus element named Step at the Subsystem block port named InBus.

path = "myModel/mySubsystem/myBlock/InBus.Step"

To programmatically get the name of the port on a In Bus Element or Out Bus Element block, use this command. block is the block handle or path.

portName = string(get_param(block,"PortName"));

To get the name of the bus element that an In Bus Element or Out Bus Element block selects, use this command.

elemName = string(get_param(block,"Element"));

To get the name of the port or selected bus element of multiple In Bus Element or Out Bus Element blocks at once, specify b as a vector of handles or as a set of paths in a string array or cell array of character vectors.

Get Port Handle

You can programmatically get the handles of the ports on a specific block or the ports to which a specific signal line connects.

To get all port handles of a block, use this command. b is the block handle or path.

h = get_param(block,"PortHandles")

To get the handles of the input and output ports of the block, enter these additional commands.

hIn = h.Inport
hOut = h.Outport

If the block represents a conditionally executed subsystem, to get the handles of the control input port, enter an additional command of this form. The command uses dot notation and the port name to extract the control input port handle from h. In this case, the port name is Trigger.

hCtrlPort = h.Trigger

To get all port handles of multiple blocks at once, specify the blocks as one of these.

blocks = [h1;h2;h3];
h = get_param(blocks,"PortHandles")

blocks = ["myModel/myBlock1";"myModel/myBlock2";"myModel/myBlock3"];
h = get_param(blocks, "PortHandles")

blocks = {'myModel/myBlock1';'myModel/myBlock2';'myModel/myBlock3'};
h = get_param(blocks, "PortHandles")

The output is a cell array. Each cell contains a structure that stores the port handles of one block. To get all the port handles of a specific block from h, use this command, where i is the index of the block in h.

hBlockPorts = h{i}

To get the handles of all ports of a specific type stored in h, you can use the arrayfun function. For example, to get the handles of all output ports stored in h, use these commands. The first command specifies a function that takes the value t as input. The function gets all output ports stored in the structure with index t. The second command defines and populates the vector named i, which contains the indices of all the structures stored in h. The last command runs the function named hFunc for each index in the vector named i.

hFunc = @(t) h{t}.Outport;
i = 1:length(h);
hOutports = arrayfun(hFunc,i)

To get the handles of the source and destination ports of a signal line, use these commands. hLine is the line handle. To get the port handles of multiple signal lines at once, specify the signal lines as a vector of handles.

hSrc = get_param(hLine,"SrcPortHandle")
hDst = get_param(hLine,"DstPortHandle")