Why do I get a "Invalid variable" error when a time table for simulation input has more than one variable?

Why can't I use a timetable with multiple variables for simulation input? I am receiving the following error: 

Invalid variable '<variable_name>' specified as input in '<model_name>'. Timetable for simulation input cannot have more than one variable.

Answer 1

[MathWorks Support Team]

This is intended behavior as of MATLAB R2022a. A timetable object can have only one variable when used for simulation input.

Consider one of the following possible workarounds:

(1) Split up the multi-variable timetable into several one-variable timetables and assign each one to a data inport, as a leaf signal for a bus-valued inport, or to a separate "From Workspace" block.

% Time in seconds
time = linspace(0,10,100)';
v1 = rand(size(time));
v2 = rand(size(time));
% Create two separate one-variable timetable objects to assign to
% separate inports or From Workspace blocks
TT1 = timetable(seconds(time),v1);
TT2 = timetable(seconds(time),v2);

.

(2) Use a timeseries object instead of a timetable object. The code below creates a timeseries object containing two variables (columns) – 'v1' and 'v2':

% Time in seconds
time = linspace(0,10,100)';
v1 = rand(size(time));
v2 = rand(size(time));
% Create a timeseries object named t, containing the time in seconds, and
% v1 and v2 variables
t = timeseries([v1,v2],time,'Name','t');

The timeseries object 't' can then be loaded in Simulink with the "From Workspace" block. Individual variables (columns) can be accessed with a "Demux" block. Refer to the image below:

(3) In case your data is originally stored in a spreadsheet, note that there is a "From Spreadsheet" block that supports multiple variables as outputs:

https://www.mathworks.com/help/simulink/slref/fromspreadsheet.html