Serial Communication Problem with Timeout

Hello,

I am trying to write a function for a piece of measurement equip I have. The problem I am having is that the measurement time is variable depending on my measurement. So if I ask the part for data while it still is measuring I get no response and my program times-out. When it is done measuring it outputs data. Is there a way to see if any data has been given before I try to read the data? As of now I am just waiting 30 seconds which is a bit of a waste of time.

function J = PR705f(P)

delete(instrfind)
timestamp = 0;
tic
s = serial(P,'BaudRate',9600,'DataBits',8,'StopBits',1);   
%Open serial Port
fopen(s)
%start remote mode
fprintf(s,'PR705')
x = 1;
pause(2)    
%Measure
fprintf(s,'M5\n\r')
pause(30)
%Record Results
fgets(s);
pause(.1)
fgets(s);
pause(.1)
tline(x,:) = fgets(s);
for x = 1:200;   
  tline(x,:) = fgets(s);
  pause(.1)
end
pause(5)
fprintf(s,'D6\n\r')
pause(.1);
tline2(1,:) = fscanf(s);
pause(5)
fprintf(s,'Q\n\r')
fclose(s)
delete(instrfind)
timestamp = toc;
save_data('MySerialFile.txt',tline2)
save_data('MySerialFile.txt',timestamp)
clear x
clear tline
clear tline2

Answer 1

[Walter Roberson]

You can check BytesAvailable of the serial object.

[Steven]

This would work if I had the instrument control toolbox...