Keithley 6514 electrometer control via RS-232

Hi,

I am trying to communicate with Keithley 6514 via RS-232. When I run my m-code Keithley responds, so it means there's a communication.

However voltage values, I am getting are incorrect.

I am using modified code, which I have found on internet:

    s = serial('COM1');
set(s,'BaudRate',9600,'Terminator','CR','Timeout',1, 'DataBits', 8, 'Parity', 'none');
fopen(s);
fprintf(s,'*rst');  %reset instrument
fprintf(s,'*idn?'); %identify the system connected
out = fscanf(s);
if strfind(out,'KEITHLEY') %&& strfind(out,'6514') %M6514
    fprintf(s,'*rst'); %reset instrument
    fprintf(s,'volt:dc:rang 200'); %set voltage range
    fprintf(s,'func "volt:dc";:read?'); %read voltage range
    out = fscanf(s);
    disp(out);
    fprintf(s,':syst:loc'); %set instrument to local use
    get(s);
    fclose(s); %close and disconnect from com port
    fclose(s);
    delete(s);
    clear s;
    out = eval(out);
    out = out*10;
    out = round(out);
    out = out/10;
    disp(out);
else
    fprintf(s,'*rst'); %reset instrument
    fprintf(s,':syst:loc')
    fclose(s); %close and disconnect from com port
    fclose(s);
    delete(s);
    clear s;
    msgbox('Check connections DMM!','MCS','warn');
end;

In the end I am getting three values, instead of one voltage value. I am getting -6.325239E-04,+2.887642E+03,+5.120000E+02, while real value is 8.236V.

I don't know where is the problem and how to solve it, but I get:

      Error using keithley_read_1 (line 19)
      Error: Unexpected MATLAB operator.

This is regarding line: out = eval(out);

Can someone help me with this?

Regards, Bart

[larbi nehari]

Hi man, i wonder if you actually made your code work ?! if yes please give us more details please, thank you

Answer 1

[Luca Lusuardi]

Actually, you have to write before voltage measurements

fprintf(s,'func "volt:dc";:read?'); %read voltage range

the following code line:

fprintf(s, 'form:elem read');

if you want read only voltage value. The standard format is [read], [time], [status]. For example, if you want time too, you have to write instead

fprintf(s, 'form:elem read, time');

Answer 2

[Walter Roberson]

Use sscanf(out, '%f') instead of eval(out)

Answer 3

[Ye Sun]

I have the same question. Anybody solved it yet? Thanks.

Answer 4

[alwathiqbellah]

Hi Guys

I'm wondering if anybody resolves this issue, I had the chance to communicate with Keithley 6514 via RS-232 through ExceLINX software, and I got output voltages from M6514 and ExceLINX but I need to communicate through Matlab to have the ability to synchronize with other outputs.