Here's an example of plotting one parameter. You don't really need the comparison of datenum with current since I put in a pause of 60s, but it is a check to see that the file really was updated. pos is used to read the file to the next line of data. I'm assuming the new data is appended to the file, which is why I increment pos each time. Not sure if this will load down your computer, but I'm hoping pause is really a sleep task:
pausetime = 60;
dirname = 'c:\myCR1000data\'; % example of directory
filename = 'CR1000_PU22_TTT_15sec_new1.csv';
file = dir(filename);
current = file.datenum;
f = figure;
pos = 1; % initial data line in file
while(1)
file = dir(filename);
if (file.datenum > current)
fid=fopen(filename);
c = textscan(fid,'%s %f %f %f %f %f %f %f %f %f %f %f',...
pos,...
'CommentStyle',...
{',,Min,Smp,Avg,Avg,Avg,Avg,Avg,Avg,Avg,Avg'},...
'delimiter',',','EmptyValue',nan);
fclose(fid);
pos = pos + 1;
c{1,1}=strrep(c{1,1},'UTC','');
CR1000_PU22_TTT_15sec.time = datenum(c{1,1},'dd/mm/yyyy HH:MM');
CR1000_PU22_TTT_15sec.HF_Low = c{1,7};
plot(f,CR1000_PU22_TTT_15sec.time, CR1000_PU22_TTT_15sec.HF_Low);
hold(f, 'on');
end
current = file.datenum;
pause(pausetime);
end