BMS Systems- ARCNet & RS 485

[remp]

Can some body explain to me the meanining of the following experssions ARCNet and RS 485. A consultant recently specified the following;

- Backbone running at 2.5Mbs using ARCNET communication?
- A local Area Network utilising RS485.?

I think I know the meaning of LON and BACNet and Modbus...they are BMS languages/protocols. Siemen and Honeywell have their own.

Where does Ethernet come into all this?

A brief explanination to broaden my basic knowledge would be appreciated or any suggested web link.

 

[xnuke]

ARCNet is an older protocol that is similar to Ethernet. I've seen it used in older Johnson Controls installations. I'm suprised at the spec for ARCNet. Most of the newer systems I've seen have an Ethernet backbone, including JC.

RS-485 is a multi-drop serial commumication bus. It's frequently used with protocols like Modbus.

You should be able to find more about these with a simple internet search.

xnuke

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