I am trying to communicate via the serial port with an device. The device uses a communication protocol in which each packet of data ends with a checksum byte. When I try to read data from the device with the fread command, Matlab does not stop reading until timeout occurs. I assumed it was waiting for a terminator character, and set terminator to empty, but matlab still doesn't know when the data is finished being sent. Is there a way to program matlab to look for the checksum byte? Should I just reduce the timeout duration and ignore the timeout warnings?