2005-05-10 08:32 AM
2011-05-17 03:06 AM
I must connect three units with protocol master\slave
have any example code function, for the serial comunication in 8051 whit the rs485 protocol? I would create a netwarok with 1 master and more slave, the slave measuring 4 o 5 parameters (Example:voltage,temperature, exc) and send at the master this data only when it comes to it asked, but if are an allarm (example temperature > 30 °C) it send only the name of alarm sensor.. the data line is an rs485 I use uPSD3334D2011-05-17 03:06 AM
hi,
rs485 is not a protocol, but a ''physical layer''. you should handle the rs485 like a ''normal'' uart (rs232) from the 8051. (see UART-section in the datasheet.) the rs232-rs485-conversion has to take place outside of the uPSD33xx.