RS232 to RS485

delene · Joined: 13 Oct 2003 Posts: 32

Can anyone please tell me what device to use to convert RS232 to RS485

Many thanks
Delene

sandyw · Guest

I may be reading this wrong but if you mean changing the RS232(uart) output from the PIC to RS485 try looking at the MAX3160 IC from maxim.

This takes the TTL levels from the PIC and can convert it to true RS232 or RS485 depending on how you set it up.

hope this helps

Sandyw

Mr. Green

zero2one · Joined: 04 Jan 2005 Posts: 1

TSchultz · Joined: 08 Sep 2003 Posts: 66 Location: Toronto, Canada

If you are just starting out with RS485 save yourself some trouble and use one of the trasceiver chips that have fail-safe features. This will ensure you always have a valid logic level when no node is transmitting. There are other ways of doing this, but with it built in the chip then you don't have to wonder if you did it right.

Also please read The Art and Science of RS485 http://www.circuitcellar.com/library/ccofeature/perrin0799/c79bppdf.pdf

If you are lookin at connecting the RS485 ot a PC, then there are a few add-on cards that work ok, or buy a converter. I like the products from BB Electronics http://www.bb-elec.com/.