I think you meant AN1057 instead of AN057. http://www.national.com/an/AN/AN-1057.pdf Otherwise, good stuff Sergio. Bruce. -----Original Message----- From: Sergio Picado [mailto:SPicado@WTIUS.COM] Sent: Thursday, February 15, 2001 9:12 AM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [PIC]:RS485&PROTOCOL Go to http://www.national.com/ and look up applications AN057, AN915 (uses 2 lines instead of 3 to talk to the chip), AN847 and the DS75176B.PDF data file. The people who came up with the RS-485 idea should be showered with praises. Cheers, Sergio -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Walter Markiw Sent: Tuesday, February 13, 2001 3:24 PM To: PICLIST@MITVMA.MIT.EDU Subject: [PIC]:RS485&PROTOCOL I need to implement a serial comunication between a pic16c74 and three 16c84s, each of which controls remotely a frecuency inverter.There is no need to handle any complex protocol,and 9600 bauds will do.I thought of RS485 because it can handle multidrop nodes over long distances (though 200 feet will do for me). Can you help me with this?My experience is very limited concerning serial communications.Is there an application note I can resort to?So far I have only found apps concerning RS232 code,but nothing on any kind of protocol to run on rs485.For what I have read,I should have to implement a token ring configuration,allowing only one node to transmit at a time.There are plenty of descriptions about this on the web,but hardly any is detailed enough as to provide the gidelines for its implementation. Thanks in advance, Walter Markiw -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu