How to calculate phase difference between 2 periodic signals recorded from oscilloscope?

I have recorded 2 signals from oscilloscope and stored it in a csv file.

I have ploted both the signals. But i need to calculate the phase difference between these 2 waves.

I have attached the csv file. consider the Channel 1 and 2.

I have plotted the code as below:

v=csvread("data.csv",2,0);
a=v(:,5); % the column you want to plot
a1=v(:,6);
ts=2e-9;   % the sampling time is available in data (excel file)
z=length(a);
t=0:ts:ts*z-ts;
subplot(2,1,1)
plot(t,a)
xlim([0 5e-7])
subplot(2,1,2)
plot(t,a1)
xlim([0 5e-7])

Answer 1

[Star Strider]

One approach —

T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/840620/data.CSV', 'VariableNamingRule','preserve')

T1 = 20482×6 table
            Var1                               Var2                        Var3       Var4        Var5     Var6
    ____________________    ___________________________________________    ____    ___________    _____    ____

    {'Record Length'   }    {'20480'                                  }    NaN             NaN      NaN     NaN
    {'Sample Interval' }    {'CH1:0.0000000020000 CH2:0.0000000020000'}    NaN             NaN      NaN     NaN
    {'Vertical Units'  }    {'CH1:V CH2:V'                            }    NaN      -2.048e-05    -0.44    6.72
    {'Vertical Scale'  }    {'CH1:1.00 CH2:2.00'                      }    NaN     -2.0478e-05    -0.48    6.72
    {'Vertical Offset' }    {'CH1:-0.04000 CH2:-0.08000'              }    NaN     -2.0476e-05    -0.52    6.96
    {'Horizontal Units'}    {'s'                                      }    NaN     -2.0474e-05    -0.44     6.8
    {'Horizontal Scale'}    {'0.0000000500'                           }    NaN     -2.0472e-05    -0.24    6.88
    {'Model Number'    }    {'WaveAce1002'                            }    NaN      -2.047e-05    -0.16    6.96
    {'Serial Number'   }    {'LCRY2150C00084'                         }    NaN     -2.0468e-05    -0.16    6.96
    {'Software Version'}    {'5.01.02.27'                             }    NaN     -2.0466e-05     -0.2     7.2
    {0×0 char          }    {0×0 char                                 }    NaN     -2.0464e-05    -0.24    6.96
    {0×0 char          }    {0×0 char                                 }    NaN     -2.0462e-05    -0.16    7.04
    {0×0 char          }    {0×0 char                                 }    NaN      -2.046e-05    -0.08    7.04
    {0×0 char          }    {0×0 char                                 }    NaN     -2.0458e-05    -0.04    7.04
    {0×0 char          }    {0×0 char                                 }    NaN     -2.0456e-05     0.08     7.2
    {0×0 char          }    {0×0 char                                 }    NaN     -2.0454e-05     0.12    7.04

% C1 = readcell('https://www.mathworks.com/matlabcentral/answers/uploaded_files/840620/data.CSV')

time = T1.Var4(3:end,:);
CH1 = T1.Var5(3:end,:);
CH2 = T1.Var6(3:end,:);

Ts = mean(diff(time))                                           % Sampling Interval

Ts = 2.0000e-09

Tsdc = Ts/std(diff(time))                                       % Check Regularity Of Sample Times

Tsdc = 2.1192e+12

Fs = 1/Ts                                                       % Sampling Frequency

Fs = 5.0000e+08

Fn = Fs/2;                                                      % Nyquist Frequency
L = numel(time)                                                 % Signals Length

L = 20480

[CH1a,CH2a,Dly] = alignsignals(CH1, CH2);                       % Align Signals, Determine Delay
fprintf('Delay = %3d Samples',Dly)

Delay = -64 Samples

[pks, locs] = findpeaks(CH1, 'MinPeakDistance',abs(Dly)*0.75);  % Peaks & Locations (Indices)
FreqCH1 = 1/mean(diff(time(locs)))

FreqCH1 = 4.9998e+06

PhaseDiffSec = Dly*Ts                                           % Samples * Seconds/Sample

PhaseDiffSec = -1.2800e-07

PhaseDiffCyc = PhaseDiffSec * FreqCH1                           % Seconds * Cycles/Second

PhaseDiffCyc = -0.6400

PhaseDiffRad = PhaseDiffSec * 2*pi*FreqCH1                      % Seconds * Radians/Second

PhaseDiffRad = -4.0210

figure
plot(time, CH1)
hold on
plot(time, CH2)
plot(time(locs), CH1(locs), '+r')
hold off
grid
xlim([[-1 1]*0.1E-5+1.2E-5])
xlabel('Time')
ylabel('Amplitude')
title('Original Signals With Located Peaks')

S1 = 0.5*sign(sin(2*pi*time*FreqCH1)) + 0.5;
S2 = sign(sin(2*pi*time*FreqCH1 - PhaseDiffRad)) + 1.1;

figure
plot(time, S1)
hold on
plot(time, S2)
hold off
grid
xlim([[-1 1]*0.1E-5+1.2E-5])
ylim([-0.1 2]*1.1)
xlabel('Time')
ylabel('Amplitude')
title('Approximate Signlal Simulation To Check Results')

.

[Varun Lokesh]

Thank you.

[Star Strider]

As always, my pleasure!