Debugging of 9-bit mode

Why not use a 8051 to read the data on the net using 9 bit mode and retransmit it on a second UART or even a software UART in 8 bit mode to your PC? You can create special markers to indicate the set 9th bit.

Meindert

Bad idea.

For exactly this reason you should never use the 9-bit UART modes. Stick with 8-n-1 for compatibility with everything. It is even better if the protocol is all in HEX and printable characters.

Using Matlab to debug RS-485 network is like using a Space Shuttle to transport a crap.

VLV

First off, don't use Matlab to observe the data unless you are using Matlab to present it in a way that wouldn't be trivial to do with something else - ie, if you are say taking and FFT and plotting that it might be worth the trouble, but if you are just dumping tables of values to the screen use something else.

Now, a way to do it: Matlab will interface to external DLL's. It's a bit of a pain to get it working, but it is doable. Write yourself a serial port interface DLL that gets the data and puts it in a format Matlab can deal with. Have your Matlab stuff call the appropriate functions in your DLL.

the 9 bit protocol for 8051 is not 8 + parity. The extra bit is supposed to be a control bit for command / data.

It was not implied that it was for parity. What was stated was the experienced opinion that a non-standard word length is probably not worth the trouble, compared to other methods of framing.

The exception might be if you are right against the limit of what can be done with a baud rate that you can't increase.

Maybe it was a better idea back in 1980 when everyone did not have a serial port on thier PC. And the chip was an 8Mhz 12 clocker. I never used it so I can't say.

Stick

the

is

The main idea behind the 9-bit mode was multiprocessor communication an other methods of framming make communication less efficient or in som cases impossible. I was using Matlab to perform algorithms on the data. thanks for all your advice

bit

I have used matlab to observe the data, strange as it may sound Matla works just fine