Problem controlling motors with COM port

Hi,

I am trying to control phyMOTION controller using MATLAB but without success. They work in the controller's own program and via NI MAX. I think the issue I have is the telegram format which is HEX. In NI MAX the telegram to move a motor forward works as follows: I enter: \0203.1-1:XX\03 and displayed is: \x0203.1-1:XX\x03 where \02 is the HEX code for STX (start text) and \03 is (end text). The rest of the telegram addresses the controller and motor and command etc.

When using MATLAB (taking care to close the communication to the COM port from NI MAX) if have tried:

vs = visa('ni','ASRL3::INSTR');
fopen(vs);
fprintf(vs, '%X','\0203.1+1:XX\03')

or as alternatives for the string fprintf(vs, '%X','\x0203.1+1:XX\x03') fprintf(vs, '\0203.1+1:XX\03')

or fprintf(vs, '%X','ETX03.1+1:XXSTX')

or as altnrnative to visa I have tried

vs= instrfind('Type', 'serial', 'Port', 'COM3', 'Tag', '');

as I said I thought the issue is the string as:

>>

sprintf('%X','ETX03.1+1:XXSTX')

ans =

45545830332E312B313A5858535458

and

>> sprintf('%X','\0203.1+1:XX\03')

ans =

5C303230332E312B313A58585C3033

not starting and ending with 02(HEX) and 03(HEX) as expected. However writign a string give:

testt =

0230332E312B313A585803

fprintf(vs, testt);

also did not work.

I have checked the Baud rate etc and all are set as expected.

Any ideas?

Thanks for your help,

Chris