Lawrence, If price is a concern and you can live with 32 slaves the SN75176 is=20 fine If you want more protection, less buss load and want to spend more=20 money on it Maxim has plenty of transceivers. Look at the end of=20 http://www.maxim-ic.com/appnotes.cfm/appnote_number/367 Regards /Ake Lawrence Lile wrote: > Yes, more precisely what I am looking for is a level shifter. My PIC=20 > will be a master and the devices on the RS485 side are all slave=20 > devices, i.e. they shaddap unless they are told to talk, so there is=20 > no problem with collissions. There is a well known=20 > protocol/language/command set what have you that talks to these=20 > devices that I need not bore you guys with there. If you are curious,=20 > they are ADAM 4015 temperature transmitters reading RTD's. (yes I know=20 > I could probably read RTD's with a PIC but I don't want to reinvent=20 > the wheel) > > You have already probably anticipated my next question - is there a=20 > simple chip that accomplishes this level shift ala' the venerable MAX23= 2? > > --Lawrence > > > >> From: Jan-Erik Soderholm >> Reply-To: "Microcontroller discussion list - Public." >> To: piclist@mit.edu >> Subject: RE: [PIC] RS232 vs RS485 >> Date: Sat, 12 Feb 2005 16:23:50 +0100 (MET) >> >> Byron A Jeff wrote : >> >> > Here's how I read Lawrence's question: >> > >> > "Can a PIC UART talk RS-485 (RS-232) without a protocol >> > converter of some sort (like a MAX232)?" >> >> Is a MAX232 a "protocol converter" ? >> I thought it was a *level* converter/shifter between >> TTL/CMOS and RS232 voltage levels. That has nothing >> to do with any protocols, if I understand correctly what >> a "protocol" is. >> >> IMHO, the answer to Lawrence is "it depends". >> If there's only one RS232 and one RS485 "node", you could >> probably live with just a level converter. But if it's a full >> RS485 "network" with multiple "nodes", you must probably >> add some "protocol" to cope with bus conflicts and collisions. >> >> So, we (or rather Lawrence) need to know more about the >> RS485 node(s) at hand. What does the actual signal/protocol >> used look like ? Is it a single RS485 node on "the line" ? >> >> Jan-Erik. >> >> >> >> --=20 >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist > > > _________________________________________________________________ > Don=92t just search. Find. Check out the new MSN Search!=20 > http://search.msn.click-url.com/go/onm00200636ave/direct/01/ > --=20 --- Ake Hedman (YAP - Yet Another Programmer) eurosource, Brattbergav=E4gen 17, 820 50 LOS, Sweden Phone: (46) 657 413430 Cellular: (46) 73 84 84 102 Company home: http://www.eurosource.se =20 Kryddor/Te/Kaffe: http://www.brattberg.com Personal homepage: http://www.eurosource.se/akhe Automated home: http://www.vscp.org --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist