Dear Sir,

Is it possible to connect various VFD s and Motor Protection Relays (MPR) using RS 485 loop topology. If yes, how it will be the Bus wiring?

 

The actual answer to your questions is that in all likelihood it is indeed possible to connect various VFDs and whatever other devices you want using RS485.

Just how you would go about implementing it is going to require a considerable amount of information you have not provided.

 

As Mr. Peterson alludes to, mention of the protocols involved is lacking.

For a discussion of more than one protocol on an RS-485 network, see this recent Control.com discussion:

http://www.control.com/thread/1303253003#1303273386

 

Folks, RS485 is a daisy-chain network which can not be configured as a star network by default, however, in the actual installations, star wiring is inevitable for many places, for example, the Control Room is located in Building 1 while other RS485 devices are located in Building 2 and 3, it would be impractical to run cables from Building 1 - Building 2 - Building 3 most of the time, especially when there is no links or "tunnel" in between Building 2 and 3, in such a case, star wiring becomes the only option. For RS485 star wiring, we would recommend CommFront's HUB-485-4, which split one RS485 bus into 4 and can be cascaded if more buses are required. For more information, you may visit: www.commfront.com for more details.

 

Hi,

Please refer to

http://www.commfront.com/knowldege-base.htm#4