Zeshan

The value of terminating resistors is 120 ohms and i am using beldan 3 shielded cable.really dont know the line resistance.should i try less baud rate as 9600?or 192000?plz help me

I have modicon m580 cpu as master and tm221c16r as slaves and etor4 as gateway.but i cant get all devices in communication

Hello. I am having 22 slaves communicating to a master on rs485 half duplex.i have selected baud rate as 38400 on a length of 800m.The problem is out of 22 devices only six are communicating .i have checked wiring,inserted termination resistor but still not getting rest of the devices alive.is it that i have selected high baud rate on a long length?this is the only problem as i am seeing it.can somebody help me on this issue