Question

Is there a way to establish a GPIB connection using MATLAB without the instrument control Tool box? (I don’t have it). Also is there a way for MATLAB to know what the external device’s RS232 parameter values are ( Baud rate, stop bit etc..). For the RS232 connection I have the following code:

% This function is meant to send commands to Potentiostat Model 263A.

% A run includes turning the cell on, reading current for time t1, turning

% the cell off, waiting for time t2.

% t1 is the duration [secs] for which the Potentiostat must run (cell is on)

% t2 is the duration [secs] to on after off

% n is the number of runs 

% port is the serial port name such as COM1

function [s] = Potentiostat_control(t1,t2,n)

port = input('type port name such as COM1', 's')

s = serial(port);

set(s,'BaudRate', 9600, 'DataBits', 8, 'Parity', 'even', 'StopBits', 2 ,'Terminator', 'CR/LF'); 

fopen(s)

%fprintf(s,'RS232?')

disp(['Total runs requested = ' num2str(n)]) 

disp('i denotes number of runs executed so far..');

for i=1:n

    i

    %data1 = query(s, '*IDN?')

    fprintf(s,'%s','CELL 1'); % sends the command 'CELL 1'

    %fprintf(s,'%s','READI');

    pause(t1);

    fprintf(s,'%s','CELL 0');

    %fprintf(s,'%s','CLEAR');

    pause(t2);

end

fclose(s)

Answer 1

For your GPIB question, does the GPIB card come with a callable library (DLL if you’re on Windows)? Matlab has an interface for calling external libraries. The basic procedure is to have Matlab parse the header file using LOADLIBRARY, then view the available functions using LIBFUNCTIONS and call functions using CALLLIB.

For your RS232 question, I don’t think there’s any way for the host side to know the device side’s parameters without external documentation.