Hi I am kalingarajan working as building automation engineer.I want to communicate with PLC through RS485.But i can communicate through RS232.Is any setting in AB plc to communicate through RS485?. otherwise how can i communicate with plc through RS485?please help me

What kind of AB PLC you use

If it is a AB PLC that is using DF1, you can get a NET AIC adapter. What I generally use is a red lion data station. ( see redlion.net ) the cheapest version costs less than any allen bradly soloution (although it does require programming, while the AB version does not ) and has the advantage that it can convert the allen bradly data to pretty much whatever else you might want: rs-485 , ethernet

You should be able to do it with Simple RS232 to RS485 converter. Which is the PLC series ?

ALLEN-BRADLEY PLC - Programmable Logic Controllers

www.aotewell.com