PST Chronos® response box with Psychtoolbox?

Hi all,

My aim is to receive key presses from a response box by PST (Chronos®) and sending it to MATLAB. 

I am aware of the function CMUBox.m in Psychtoolbox, which is supposed to receive responses from PST response boxes by specifying which USB port the response box is connected to, but it seems that MATLAB does not even recognise the box. I'm working with Windos 7 and baud rate is 19200 and FIMI is off. Code is below.

handle = CMUBox('Open','pst','COM4')

CMUBox: Using PST serial response button box!
Error in function OpenSerialPort:  Usage error
Error opening serial port device COM4 [\\.\COM4] - No such serial port device exists! (2) [ENOENT].

I know that CMUbox.m was written to receive keypresses from another response box, PST Serial Button Response Box, so I am aware of the option that PST does not want their device to be linked to MATLAB and made sure to prevent this in newer response boxes like Chronos®. 

I am wondering if despite that, anyone has experience with this and/or is aware of a workaround?

Best wishes


Are you sure COM4 exists? The error message suggests otherwise. 

Hi Allen_Ingling,

Did you ever get this issue resolved? We are having a similar problem with Chronos device compatibility and Psychtoolbox. Please let me know.