Author Topic: RS485 Interface  (Read 3146 times)

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Offline helpTopic starter

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RS485 Interface
« on: November 04, 2007, 05:10:51 AM »
Hi,

I would to use RS485 for my interfacing between PC and few other serial module.

What's the step should i start on the Hardware and Firmware(Protocol) side?
Example I had 3 node (node1=PC, node2=MCU1, node3=MCU2).
My PC only had one serial RS232 port, and the MCU also only had one serial. If i would like to use standard RS232 for all the node in interface, so i just have to put a RS485-RS232 convertor? If yes, how the node recognize the protocol?

Did anyone have a simple sample code for RS485? I just want to get some idea. I had no problem with using RS232.

Thank You.

Offline Admin

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Re: RS485 Interface
« Reply #1 on: November 07, 2007, 07:18:55 PM »
Why not use rs232 entirely? Or USB?

You can buy rs232 to USB adaptors. That should make your life easier . . .

Offline helpTopic starter

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Re: RS485 Interface
« Reply #2 on: November 09, 2007, 12:23:29 AM »
Why not use rs232 entirely? Or USB?

You can buy rs232 to USB adaptors. That should make your life easier . . .

Hi,

If i have more thn one Slave. We should use rs485, am i rite?
I had found one chip FT232R. It can convert USB to rs485. Do you know this chip limitation? How fast the data transfer can be transmit and how far the cable can be lay?

Thank You.

Offline JonHylands

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Re: RS485 Interface
« Reply #3 on: November 09, 2007, 07:06:26 AM »
I just hooked an FT232 to a MAX485 last night, to drive an RX-64 servo (which runs on an RS-485 multidrop network).

The FT232 can do up to 2.0 Mbps. The RX-64 runs at 1.0 Mbps, and it has no trouble. The really nice thing is the FT232 drivers set up a virtual serial port, so it can be used just like a normal serial port.

- Jon

 


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