these is regarding multi controller communication actually i am using one master that recieve from more than 1 slave which act as transmitter (all controller here are 8051). system works properly till only two transmitter are connected but data get corrupted when more than 2 transmitter are connected. i am using uart protocol in which master receive 8 bit char from each transmitter. so plz help me with some solution
You haven't given much information about how you make sure that only one slave at a time will try to send.
And you haven't given much information about the electrical connection, i.e. if multiple passive slaves may still be connected in a way that they load the signal line too much for a single active slave transmitter to be able to correctly send data.
Obviously, this are things you should have spent a bit of time with before making this hardware design - maybe you could supply us with some of the thoughts you had and the decisions you made?