“How can I write two M‑scripts: one to disable signal logging across the whole Simulink model (masked subsystems), and another to enable logging only for selected signals

I’ve developed a script that successfully disables all logged signals in a Simulink model when it's used in a standard configuration. However, I’m facing an issue when applying the same script to the exact same model after it has been placed inside a masked subsystem. In this masked context, the script no longer disables the logged signals as expected. This behavior also applies to signal logging operations in general. Could you please help me understand why this is happening and guide me on how to resolve it?

Script :

% %% Disable all signal logging in the given Simulink model
% %% Model
modelPath = '***';  % Update with your actual path
addpath(fileparts(modelPath));
load_system(model);
model = '***';
% %% Load the model if not already loaded
if ~bdIsLoaded(model)
    load_system(model);
end
% %% Turn off model-level logging
set_param(model, 'SignalLogging', 'off');
set_param(model, 'SaveOutput', 'off');
set_param(model, 'SaveState', 'off');
% %% Turn off DataLogging on all ports and lines, including variants
ports = find_system(model, 'MatchFilter', @Simulink.match.allVariants,'FindAll', 'on','Type', 'Port');
lines = find_system(model, 'FindAll', 'on', 'MatchFilter', @Simulink.match.allVariants, 'Type', 'Line');
for i = 1:length(ports)
    try
        set_param(ports(i), 'DataLogging', 'off');
    catch
        % Some ports may not support DataLogging
    end
end
for i = 1:length(lines)
    try
        set_param(lines(i), 'DataLogging', 'off');
    catch
        % Some lines may not support DataLogging
    end
end
% %% Unmark all signals for SDI streaming
try
    Simulink.sdi.clear;
    Simulink.sdi.setStreaming(false);
    Simulink.sdi.setAutoSave(false);
    Simulink.sdi.setRecordData(false);
catch
    % Ignore if SDI is not available
end
% %% Disable logging for all blocks including variants
blocks = find_system(model, ...
    'FollowLinks', 'on', ...
    'LookUnderMasks', 'all', ...
    'MatchFilter', @Simulink.match.allVariants);
for i = 1:length(blocks)
    try
        set_param(blocks{i}, 'DataLogging', 'off');
    catch
        % Some blocks may not have DataLogging parameter
    end
end
fprintf('✅ All signal logging disabled for model: %s\n', model);

Answer 1

[Mark McBroom]

Your first 2 find_system() calls don't look under masks. Try adding 'LookUnderMasks','all'

[Santhosh Kumar]

Thank you its working.