My contention (on this very contentious thread) is that one defines the size of the "word" in question and that definition works for that conversation. The next conversation might well use a different defintion.
Two days ago, I posted the post below in the thread called "rs 485 no talk!!
I used the term 'word' to describe the bit pattern of a single 'word' in a Modbus RTU transmission.
My question to those advocates of an unchangeable, fixed length definition for 'word' (asserted to be 16 bits by majority expression in this thread), is:
what term should I have used for 'word', where the word set of bits being talked about consists of a start bit, an 8 bit data word, a parity bit and a stop bit?
I await your advice and replies.
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The scope screen shots are very interesting. Thanks for posting those.
Initial section of exploded view
Is RS-485 negative logic? (logic zero = positive voltage) ?
How do you read the first word?
Is the initial transition to - 3V preparation to drive to +3v or is the -3V a logic state bit?
Meaning, is the -3V the start bit or is +3V the start bit?
Is the first
word (start bit, 2 nibbles/8 bits of data, parity, stop bit)
1 0111 1101 00 or
0 1000 0010 11 ?
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