Serial communication with a header and a terminator

I want to send two uint16 numbers through the serial communication. The DSP wants the header and terminator to be equal to 'S' and 'E'. The command serial does not have an option for 'header' but it has an option for defining 'terminator'.

obj=serial(USBport);
obj.BaudRate=9600;
obj.Terminator='E';
obj.ByteOrder='LittleEndian';

To use the header I am writing

fwrite(obj,'S','char')

Now in order to send the two numbers I am using:

 x = int16(1);
fwrite(obj,[x x],'int16')

I know that in each fwrite command an 'E' will be sent as well. How can I avoid this? Can I just send E at the end of the commands with another fwrite?

I am using this block to configure the DSP for receiving data.

[Walter Roberson]

"I know that in each fwrite command an 'E' will be sent as well."

That should not happen. fprintf() can send terminators when you are not expecting them, but fwrite should not send the terminator unless you happen to send one as data.

However, you would want to check to see whether it sends each fwrite() as a separate packet, which could be a problem for USB over serial.

[Marzieh Karami]

You are right! fwrite does not automatically send terminator.

Answer 1

[Gayatri Menon]

Hi,

Protocol Decoder block and Protocol Encoder block might be useful in such scenarios.

For more info, refer the following links

• Protocol Encoder
• Protocol Encoder
• Encode and Decode Serial Data Using C2000-based Hardware

Hope this helps

Thank you

Regards

Gayatri