How to read from serial port with matlab (timeout problem) ?

Dear all,

I want write/read to/from a serial port with matlab, to communicate with a trinamic step motor. I checked that I properly write to the port with port monitor software, but nothing comes out of the port when I attempt to read from it (I just get a timeout, even if I change the time out time to 20 sec). I've looked into the trinamic documentation, but the example they provide (a simple fread) doesn't work.

The point is I manage to read from the port with a Labview "VISA read" VI, but I can't match what this VI does with matlab... And because I'm a rookie when it comes serial port communication, I don't even know where to start...

Any suggestions ?

Thanks !

Answer 1

[Anusha B]

The cause of the issue may be similar what is mentioned in this link:

http://www.mathworks.com/matlabcentral/answers/98527-why-does-a-serial-connection-to-a-ublox-gps-device-from-matlab-timeout

One way to check this can be to see if you can read and write to serial port of any other hardware device using MATLAB.

Hope this helps.

[Stéphane]

Thanks for your reply.

I've updated the driver but doesn't change anything.

I've seen that I may have to write all the 9 bytes at once, but I'm not sure how to do that, so far I've only managed to write one after the other...

Answer 2

[Stéphane]

Thanks for your reply.

I've updated the driver but doesn't change anything.

I've seen that I may have to write all the 9 bytes at once, but I'm not sure how to do that, so far I've only managed to write one after the other...

If I can be more accurate : I need to write 9 bytes at once (and read them), something like 01 00 06 02 00 00 00 00 07...

[Dp]

Hi were you able to write and read with Matlab? I plan on doing the same thing with the tmcm1633