Problem with manchester code for RF

[Dave]

dhouston, How can you say: Manchester encoding is not immune from noise but does have built-in error detection. What is the "built-in error detection"? This is news to me as I write software for Tire Pressure Monitoring equipment which uses Manchester coding. Please explain.....

Dave Purola,
N8NTA

[dhouston]

dhouston, How can you say: Manchester encoding is not immune from noise but does have built-in error detection. What is the "built-in error detection"? This is news to me as I write software for Tire Pressure Monitoring equipment which uses Manchester coding. Please explain.....

If you don't see a change of state at the middle of a bit period, you've detected an error which is usually the result of noise if you are using it over a wireless link or a collision if you're using it over a wired link (e.g. 802.3, X-10). See the last paragraph at http://www.wildpackets.com/support/c...ignal_encoding.

[Dave]

dhouston, I call that type if "error detection" signal integrity, not error detection. You could have a noise source producing edge changes at the same rate as the baud rate you are trying to detect. Where is the error detection then?

Dave Purola,
N8NTA

[dhouston]

dhouston, I call that type if "error detection" signal integrity, not error detection. You could have a noise source producing edge changes at the same rate as the baud rate you are trying to detect. Where is the error detection then?

Call it what you like. I'll call it what it is.

[dhouston]

You could have a noise source producing edge changes at the same rate as the baud rate you are trying to detect. Where is the error detection then?

And where is the error if no low state gets changed to a high state?

[Dave]

dhouston, Try deciphering 1 individual transmission of 128 data bits (256 states) with 4 or more transmitters being keyed at the same time.... The data states at the receiver might look good but what about the actual data..... Like I said... Signal integrity

Dave Purola,
N8NTA