mpcverbosity off;                           % turn off mpc messages

% create plant model
plant = rss(4,4,4);                         % random state space
plant.D = 0;                                % set D matrix to zero

% set signals type in plant model
plant = setmpcsignals(plant,'MV',1,'MD',3,'UD',4,'MO',1,'UO',[3 4]);

% create MPC object
mpcobj=mpc(plant,1);                        % sampling time = 1 second

% get input signal names
getname(mpcobj,'input',1)                   % get name of first input signal
ans =
    'MV1'

getname(mpcobj,'input',2)                   % get name of second input signal
ans =
    'MV2'

getname(mpcobj,'input',3)                   % get name of third input signal
ans =
    'MD1'

getname(mpcobj,'input',4)                   % get name of fourth input signal
ans =
    'UD1'

% get output signal names
getname(mpcobj,'output',1)                   % get name of first output signal
ans =
    'MO1'

getname(mpcobj,'output',2)                   % get name of second output signal
ans =
    'MO2'

getname(mpcobj,'output',3)                   % get name of third output signal
ans =
    'UO1'

getname(mpcobj,'output',4)                   % get name of fourth output signal
ans =
    'UO2'

% alternative ways to retrieve names
mpcobj.Model.Plant.InputName{2}              % second plant input
ans =
    'MV2'

mpcobj.ManipulatedVariables(2).Name          % second manipulated variable
ans =
    'MV2'

mpcobj.Model.Plant.InputName{4}              % fourth plant input
ans =
    'UD1'

mpcobj.DisturbanceVariables(2).Name          % second disturbance variable
ans =
    'UD1'

mpcobj.Model.Plant.OutputName{4}             % fourth plant output
ans =
    'UO2'

mpcobj.OutputVariables(4).Name               % fourth plant variable name
ans =
    'UO2'