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start & stop bits of modbus rtu mode

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AliBahar

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Hi
In Modbus RTU mode, messages start with a silent interval of at least 3.5 character times.
I want to make it ( idle mode in interval of 3.5 character times ) using uart of typical microcontroller.
by the way how slave recognizes the silent interval when the stream of data receives to RX.
 
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Kurenai_ryu

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it means that you have to stop transmitting for 3.5 times a character, for example if you are communication at 9600bps 8n1, each character takes about 1ms... after you send a data frame, you have to wait at least for 4ms (3.5ms but meh) it doesn't mean that you send 0xFF or 0x00.. you just have to wait for that amount of time... (also remember that when you send a data packet you can't wait over 1.5ms between characters inside the data packet or the slave could restart the packet recieving...)

all of these could be implemented in a slave via timers and interrupts..
 
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