can anyone giv algorithm for multimaster system using rs485
bus(SN75176 rs485 transreceiver). thanks a lot
you can't have a multimaster 485. For multimaster, have a look at
J1708 (really peer to peer, but that should satisfy you) another
option would be TIA 1939. If all devices are in the same box, then
SPI or IIC would be options.
i am currently using P89LPC922 microcontroller with SN75176 rs485
transceiver(master-slave system...where master polling slave) using
multi processor communication. now want to change to multimaster
communication like ethernet(where need to check if bus idle then
device communicates).any suggestions....thank u erik for
While there are implementations of Ethernet and TCP/IP for 8051's,
I think that Controller Area Network (CAN) would meet your needs
quite well. There are quite a few 8051 parts with built-in CAN
controllers and if you don't need the higher level protocols like
CANOpen or DeviceNet (few people do), then you can communicate from
one node to any other with good determinism. I learned CAN for 8051s
using Silabs C8051040 micros running C compiled using the Keil tools.
Worked well and I put CAN on just about every project I work on
(using 8051, PIC, dsPIC, and now...ARM7 processors). No regrets
TIA 1939 (which is a CAN derivative) is much more multimaster
oriented than CAN,
Yes, like Rich states, you do not need implement the whole kit and
kaboodle, but for multimaster I would refer more to 1939 then CAN.
The hardware for CAN and 1939 is identical, but 1939 has more
multimaster 'hints' than CAN.
Thank u very much for ur suggestions.:))
is it a standard method to use master polling ...any other way by
using rs485 itself?....thanks in advance....