Level 2 S-Function block port sampling mode error

When I try to run a model containing Level-2 m-code S-Function block I have created I get the following error:

Level-2 MATLAB S-function 'wrappedGymPyEnvL2Sfcn' in 'test_sfcn/Level-2 MATLAB S-Function1' does not have a 'SetInputPortSamplingMode' method. When a Level-2 MATLAB S-function with multiple output ports has dynamic sampling mode setting for any of its ports, it is necessary to register a 'SetInputPortSamplingMode' method

In this block I set the input port size and one of the output port sizes based on a dialog parameter. My setup function for this block is shown below:

function setup(block)

    block.NumDialogPrms     = 3;
    block.DialogPrmsTunable = { 'Nontunable' ...
                                , 'Nontunable' ...
                                , 'Nontunable' ...
                               };


    % Register number of ports
    block.NumInputPorts  = 1;
    block.NumOutputPorts = 2;

    % Setup port properties to be inherited or dynamic
%     block.SetPreCompInpPortInfoToDynamic;
%     block.SetPreCompOutPortInfoToDynamic;

    % Override input port properties
    
    % action input
    block.InputPort(1).Dimensions        = [1, block.DialogPrm(1).Data];
    block.InputPort(1).DimensionsMode    = 'Fixed';
%     block.InputPort(1).Dimensions = [1, 100]; % maximum dimensions
    block.InputPort(1).DatatypeID  = 0;  % double
    block.InputPort(1).Complexity  = 'Real';
    block.InputPort(1).DirectFeedthrough = false;
    
    % Override output port properties
    
    % the state values
    block.OutputPort(1).Dimensions       = [1, block.DialogPrm(2).Data];
    block.OutputPort(1).DimensionsMode = 'Fixed';
%     block.OutputPort(1).Dimensions = [1, 100]; % maximum dimensions
    block.OutputPort(1).DatatypeID  = 0; % double
    block.OutputPort(1).Complexity  = 'Real';
    
    % current reward value
    block.OutputPort(2).Dimensions        = [1, 1];
    block.OutputPort(2).DimensionsMode    = 'Fixed';
    block.OutputPort(2).DatatypeID  = 0;  % double
    block.OutputPort(2).Complexity  = 'Real';
    
%     block.OutputPort(1).SamplingMode = 'Sample';
%     block.OutputPort(2).SamplingMode = 'Sample';

    % Register sample times
    %  [0 offset]            : Continuous sample time
    %  [positive_num offset] : Discrete sample time
    %
    %  [-1, 0]               : Inherited sample time
    %  [-2, 0]               : Variable sample time
    block.SampleTimes = [0 0];

    % Specify the block simStateCompliance. The allowed values are:
    %    'UnknownSimState', < The default setting; warn and assume DefaultSimState
    %    'DefaultSimState', < Same sim state as a built-in block
    %    'HasNoSimState',   < No sim state
    %    'CustomSimState',  < Has GetSimState and SetSimState methods
    %    'DisallowSimState' < Error out when saving or restoring the model sim state
    block.SimStateCompliance = 'DefaultSimState';
%     block.SimStateCompliance = 'DisallowSimState';

    block.RegBlockMethod('InitializeConditions', @InitializeConditions);
    block.RegBlockMethod('Outputs', @Outputs);     % Required
    block.RegBlockMethod('Update', @Update);
    block.RegBlockMethod('Terminate', @Terminate); % Required
    
  %
  % SetInputPortSamplingMode:
  %   Functionality    : Check and set input and output port 
  %                      attributes and specify whether the port is operating 
    %                      in sample-based or frame-based mode
    %   C MEX counterpart: mdlSetInputPortFrameData.
    %   (The DSP System Toolbox is required to set a port as frame-based)
    %
    % block.RegBlockMethod('SetInputPortSamplingMode', @SetInpPortFrameData);

end

No matter what I do I cannot get rid of this error. I tried adding the following SetInputPortSamplingMode function (see the last commented statement in setup:

function SetInpPortFrameData(block, idx, fd)
  block.InputPort(idx).SamplingMode = fd;
  block.OutputPort(1).SamplingMode  = fd;
end

But if I do this, then I get the following error:

'test_sfcn/Level-2 MATLAB S-Function1' has unknown frame status for its output port 2. When all input ports have known frame status, then all output ports must have known frame status

To be honest though, I haven't a clue what this SetInputPortSamplingMode stuff is about, because as far as I can tell, it is not documented anywhere, so I would also welcome a link to documentation if I have missed it.

Answer 1

[Zhimin Wang]

function SetInpPortFrameData(block, idx, fd)

block.InputPort(idx).SamplingMode = fd;

block.OutputPort(1).SamplingMode = fd;

block.OutputPort(2).SamplingMode = fd;

end