building long wire communication

[indynetra]

long wire communication

hi all,
I am planning to build a long wire master slave communcation system with less no: of wires . that i need around 2 km distance with many slave systems ( < 128). my question is which protocol is best suited for this system and welcomes design ideas ,circuits etc

thanks
indy

 

[7rots51]

Re: long wire communication

Hello
TI company have SN65HVD22D and similars for RS485 communication for long distances and noisy environment,you can use RS485 repeaters for more distances if you want.

You can MODBUS protocol for master slave operation,see w*w.m*odbus.org

If u have single master and slave (point to point) then you can use zarlink ST-BUS and MT9172 IC,it is suitable for 5km cables with 1 bit error in millions at this lenght.

bye

 

[dudu]

Re: long wire communication

ethernet is most stable and reliable even new, there will be a new stander with power on ethernet

 

[indynetra]

Re: long wire communication

does anybody hav source for smbus implementation on uC ??, i would like to know more about power over ethernet

thx
indy

 

[artem]

what is about i2c and CAN

 

[koky]

Re: long wire communication

I have tested RS485 with vulgaris 75176 at 4.2 Km @ 9600 bps and 2 slaves, the wire was 0.7mm telephone cable.
I don't understand the question of protocol, the distance is un electrical factor, you can use what you want, i use my protocol with 16bit crc, so i can make all that i think

 

[papyaki]

Re: long wire communication

Hi,

See these topics :

**broken link removed**

**broken link removed**

 

[ash]

You should ac in your design, problems may occur while working with dc current in long distances.