How do I parse binary string

[azavarsky]

Hi folks,

I am reading a binary string from a campbell sonic anemometer. It is transmitted via RS 232 9600 baud. The problem is as follows:

I am reading the input buffer once in a while(every 300 ms). The outpit of the sonic is much faster(every 30ms). Then there are a certain amount of bytes stored which I read. To get a proper value I have to find 2 termination bytes HEX AA and  HEX 55. A complete sentence consists of 12 bytes 10 bytes each U8 values and 2 bytes termination. How do I search for them?

My idea was to see how much bytes I read, convert each to a binary array and then show them as boolean array all together(see attached VI). this works but I can't find the right binary expression for Hex AA and 55. And it is also interersting that the first collumn(bit 0) and the last one (bit 7) always stay "false". Am I doing something wrong?

[Hooovahh · Accepted solution]

So it would have been more useful if you would have posted example data that was read.  Since I didn't have any I made some up.  The attached VI will search for locations where the hex byte AA then 55 are found.  It then breaks up the sections of data using this information.  I wrote it two ways because as I was typing this I thought of a better way that uses string functions to break up the data into an array of data.

[azavarsky]

Thanks,

I added my data to your little program, attached. It seems to work. Attached is also a pic with sample data viewed in a terminal program. I will try it now with my serial routine.

Alex

[azavarsky]

Attached is my solution.

Thanks a lot.

any suggestions and improvements are very welcome.

ALex