Why do I get "Error using ^" after clicking "Run COM" in the MATLAB R2025a Signal Integrity Toolbox, Channel Operating Margin (COM) Manager?

I'm following the Channel Operating Margin (COM) for Serial Link tutorial from the Signal Integrity Toolbox. I'm following the tutorial exactly, not trying to make any modifications. I get to Step 5 and click "Run COM" in the Channel Operating Margin (COM) Manager. After running for a bit, I get the error: 

Error using ^ (line 52)
Incorrect dimensions for raising a matrix to a power. Check that the matrix is square and the power is a scalar. To operate on each element of the matrix individually, use POWER (.^) for elementwise power. 

Why is this happening? I've attached the full MATLAB command window output below:

Processing 1/5: C:\myRoot\COM_100G_KR\interfaces\100G_KR\pre_sims\Crosstalk\default.ssm\qcd\qcd_ttte_clearance1\qcd_ttte_clearance1.nc.s20p


Warning: COM controls for DIAGNOSTIC and DISPLAY_WINDOW turned off because of limitations in com_ieee8023_93a.m for MATLAB versions 14b and newer.
> In comGUI>comWrapper (line 574)
In comGUI>run_com_Callback (line 365)
In matlab.ui.internal.controller.uicontrol/UIControlController/triggerActionEvent (line 76)
In matlab.ui.internal.controller.uicontrol/UIControlPushButtonController/handleEvent (line 29)
In matlab.ui.internal.controller.uicontrol.UIControlController>@(varargin)obj.handleEvent(varargin{:}) (line 71)
In viewmodel.internal.factory.ManagerFactoryProducer>@(src,event)callback(src,viewmodel.internal.factory.ManagerFactoryProducer.convertStructToEventData(event)) (line 76)
Creating s4p's . . . done.

Running COM . . .
This is NOT an official IEEE document.
Revision: 2.95 This is a computation example for exploring COM and ERL for projects like IEEE P802.3bj/b/bs/cd/ck with some exploratory extensions and is not normative or official
reading file 1 2 3 4 5
reading file Error using ^ (line 52)
Incorrect dimensions for raising a matrix to a power. Check that the matrix is square and the power is a scalar. To operate on each element of the matrix individually, use POWER (.^) for elementwise power.

Error in com_ieee8023_93a_295 (line 642)
MDFEXT_ICN=sqrt(2*chdata(i).delta_f/param.f2*sum( chdata(i).Aicn^2*PWF(1:index_f2).*abs(MDFEXT(1:index_f2)).^2)); %eq 46
^
Error in comGUI>comWrapper (line 668)
comresults = comFunction(cfg_name,...
^^^^^^^^^^^^^^^^^^^^^^^^
Error in comGUI>run_com_Callback (line 365)
comWrapper(comdat,com_template_xls_fn,com_ieee8023_93a_fn,sit_csv_write_path,handles);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


Error using matlab.ui.internal.controller.uicontrol.UIControlController/triggerActionEvent (line 76)
Error while evaluating UIControl Callback.

 

Answer 1

[MathWorks Support Team]

This error is known to occur when you don't use the correct "COM config path" in Step 4 of the Channel Operating Margin (COM) for Serial Link tutorial.

Using the default COM config path: "config_com_ieee8023_93a_50GBASE_KR_postd1p0_exp.xls" results in the given error. The COM config path needs to be changed to "config_com_ieee8023_93a_3ck_d1p3_KR_09_01_2020.xlsx" for this example. This is shown in the screenshot of Step 4 of the documentation, although the documentation does not directly instruct to do so.

Our developers are aware of this, and they shall consider updating the documentation to better specify this step.