MATLAB: How to set the signal logging parameters for a line in the Simulink model from the MATLAB command line

blockdecimatelogmaxdatapointssimulink

I would like to access all of the Signal Properties dialog box parameters from the command line. Starting from the line handle I was able to access some of them such as Test Point, Signal Name etc. However, I cannot find the properties for the following parameters:

1. "Log Signal Data"

2. "Limit Max Data Points To"

3. "Decimation"

The rest of the parameters can be accessed as follows:

% if lineHandle is the handle to a signal (connecting line) in a model then
set_param(lineHandle, 'testPoint', true);
set_param(lineHandle, 'Name', 'x1');

I would like to know how the above listed parameters ("Log Signal Data", "Limit Max Data Points To" and "Decimation") can be set from the command line.

Best Answer

The ability to set these signal logging parameters for a line from the MATLAB command line starting from the line handle is not available in Simulink 6.4 (R2006a) or any previous release.

However, these properties can be set from the command line by starting from the block handle instead of the line handle. Thus, if it is required to set the signal logging properties for a particular line, then one can start from the block whose outport is connected to that line and obtain the 'PortHandles' property from this block handle.

h = get_param(gcbh, 'porthandles');
op = h.Outport;
set_param(op, 'DataLogging', 'on')
set_param(op, 'DataLoggingDecimateData', 'on')
set_param(op, 'DataLoggingDecimation', '2')
set_param(op, 'DataLoggingLimitDataPoints', 'on')
set_param(op, 'DataLoggingMaxPoints', '5000')

The ability to access these properties starting from the line handle is being considered for incorporation into a future release of Simulink.

Related Solutions

MATLAB: How to set the ‘Datalogging’ property for individual signals in the model from the command line in Simulink

To set the individual signal 'DataLogging' property you will need to find the line in the model corresponding to the selected signal. Then the 'DataLogging' property in the 'Srcport' object of the line needs to be set. If the model in question is the current model, and the name of the signal is 'DesiredSignal', the following code will set the 'DataLogging' property to 'on':

% First, find all of the lines in the system
Sig_handle = find_system(gcs, 'FindAll', 'on', 'type', 'line','Name','DesiredSignal');
Srcport_handle = get_param(Sig_handle,'SrcPortHandle');
set_param(Srcport_handle,'DataLogging','on');

MATLAB: How to check the ‘Signal name must resolve to Simulink signal object’ signal property from command-line

Manipulating parameters of a signal and other Simulink objects can be performed using "get_param" and "set_param" functions. Although parameters of a signal such as the signal name and "Signal name must resolve to Simulink signal object" are changed in the graphical user interface by changing the parameters of a signal line, under the hood these are properties of the outport where the signal originates. So instead of using set_param to operate on the signal line it should be used to operate on the outports where the signal originates.

The 'Signal name must resolve to Simulink signal object' dialog parameter corresponds to the 'MustResolveToSignalObject' parameter of a block's Inport or Outport handle. However, this parameter is read-only for an Inport handle and therefore can only be set via an Outport handle.

In order to set the "MustResolveToSignalObject" parameter the signal must have a name. If it does not then Simulink will produce an error notifying you that this parameter cannot be changed when the name of a signal is empty.

The following steps can be used from the MATLAB command prompt or a MATLAB script to achieve this functionality:

1. Find all inport and outport blocks in the top-level system:

outport_blocks = find_system(gcs,  'SearchDepth', 1, 'BlockType', 'Outport');
inport_blocks = find_system(gcs,  'SearchDepth', 1, 'BlockType', 'Inport');

where gcs is the current model.

2. Ensure that the output signal of all Inport blocks has MustResolveToSignalObject= 'on':

for i=1:length(inport_blocks)
   ph = get_param(inport_blocks{i}, 'PortHandles');
   set_param(ph.Outport, 'MustResolveToSignalObject', 'on') ;
end

3. Since it is not allowed to set the 'MustResolveToSignalObject' parameter of an inport handle, trace the signal to the upstream source block of each Outport block and set its Outport handle to MustResolveToSignalObject='on'. Also, since the source block may have multiple outputs, ensure that the correct signal is set by comparing signal names:

for i=1:length(outport_blocks)
   ph = get_param(outport_blocks{i}, 'PortHandles');
   signal_name = get_param(ph.Inport,'Name');
   block_pc = get_param(outport_blocks{i}, 'PortConnectivity');
   src_ph = get_param(block_pc.SrcBlock, 'PortHandles');
   src_outports = src_ph.Outport;
   for j=1:length(src_outports)
      if strcmpi(get_param(src_outports(j), 'Name'), signal_name)
        set_param(src_outports(j), 'MustResolveToSignalObject', 'on');
      end
   end
end

Best Answer

Related Solutions

MATLAB: How to set the ‘Datalogging’ property for individual signals in the model from the command line in Simulink

MATLAB: How to check the ‘Signal name must resolve to Simulink signal object’ signal property from command-line

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