RS 485 shielding and grunding

[Shek]

rs 485 shielding

HI, I'm developing a communication net withing 8051 microcontrollers using a rs485 half duplex bus. Do I have to connect ground to the shield? or do I have to get another TP to get ground through it? The t6hing is that the bus is up to 1km long and I have about 128 microcontrollers to hang on it, so how do I ground them all ( the microcontrollers are feed by batteries)??

 

[Regnum]

Take a look at the attachment

 

[papyaki]

Hi,

Look at page 8 of this app. note from NS :

h**p://www.national.com/an/AN/AN-1057.pdf

* = t

 

[marie65]

Hi,
Just to remember that the normal tranceiver for RS485 allow only 32 nodes to be conected on the same bus. You can use new designs from Maxim (maybe other companies, too) that allow 128 nodes or you will have to use repeaters.

 

[rainsun]

u can use CAN bus.