function CompTF(optic, exc, sens)
    %
    % ----------------------------------------------------------------------
    % for KAGRA VIS
    % The code to compare the simulation and measurement
    % Coded by A Shoda on 2018/4/4
    %
    % optic: optic, such as 'PR3', 'BS'
    % exc: excitation channel, such as 'LIM', 'YIP', or 'GASF1'
    % sens: monitor signal, such as 'LVDT_IPL', 'OSEM_IMT', or 'Oplev_PTM'
    % **OPTIONAL** (not yet implemented)
    % status = 0,1: default:0 = undamped, 1 = damped
    % ----------------------------------------------------------------------
    % This code is for adjusting the gain_act numbers
    % ----------------------------------------------------------------------

    %% PRELIMINARY
    clear all;                     % Clear workspace
    close all;                     % Close plot windows
    addpath('../../utility');      % Add path to utilities
    addpath('servofilter');        % Add path to servo
    g = 9.81;                      % Gravity constant
    freq=logspace(-2,2.5,1001);

    %% MODEL IMPORT
    load(strcat(optic,'mdl.mat'));  % Import ss model
    DefaultParameters;    % Import default servo filters
    %load(strcat(optic,'mdl_0params.mat'));
    mdlfile='typeBsimctrl';   % typeB ver.180313
    st     =linmod(mdlfile);          % Linearize simulink model
    invl   =strrep(st.InputName, [mdlfile,'/'],'');
    outvl  =strrep(st.OutputName,[mdlfile,'/'],'');
    sysc0  =ss(st.a,st.b,st.c,st.d,'inputname',invl,'outputname',outvl);

    %% define signals
    
    
    
end