AVR-Chat

Hi,dears
I want connect AVR(master) to micromotion flowmeter(slave).this 
connection base on Rs485 plz help me for Modbus Protocol On AVR.

http://www.modbus.org/ - The specifications are free.

You'll find the Modbus protocol to be quite simple.  I wrote a small  
slave for one of those "Other" microcontrollers in a few days.  Sorry  
no code for a master.

You'll need an RS485 transceiver.  I like the Maxim MAX483, myself.   
There are others.

Phil

On Jan 26, 2009, at 10:05 PM, babak wrote:

> Hi,dears
> I want connect AVR(master) to micromotion flowmeter(slave).this
> connection base on Rs485 plz help me for Modbus Protocol On AVR.
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

I don't know much about the micromotion flowmeter but I did something
similar with the PNI Micromag 2 magnetic field sensor. I just downloaded the
manual for it and wrote a program in assembler to read the device by
bitbanging.

Zack

On Mon, Jan 26, 2009 at 10:05 PM, babak <babak1983ir@yahoo.com> wrote:

>   Hi,dears
> I want connect AVR(master) to micromotion flowmeter(slave).this
> connection base on Rs485 plz help me for Modbus Protocol On AVR.
>
> 
>


[Non-text portions of this message have been removed]

On Tue, Jan 27, 2009 at 04:05:59AM -0000, babak wrote:
> Hi,dears
> I want connect AVR(master) to micromotion flowmeter(slave).this 
> connection base on Rs485 plz help me for Modbus Protocol On AVR. 

Serial Modbus is an asynchronous serial. The protocol specification is
available for download and written better than most. I had no problems
understanding the protocol. Found a Windows utility from England that
helped, I could use it to generate and receive arbitrary commands and
view the data sent/received with a raw display the program included. The
free version would run for 10 minutes which was perfectly fine for my
use.

-- 
David Kelly N4HHE, dkelly@HiWAAY.net
========================================================================
Whom computers would destroy, they must first drive mad.

Google is your friend, look up "modbus" with Google, or on wikipedia.

DLC

babak wrote:
> Hi,dears
> I want connect AVR(master) to micromotion flowmeter(slave).this 
> connection base on Rs485 plz help me for Modbus Protocol On AVR. 
> 
> 
> ------------------------------------
> 
> Yahoo! Groups Links
> 
> 
> 

-- 
-------------------------------------------------
Dennis Clark          TTT Enterprises
www.techtoystoday.com
-------------------------------------------------

The online Modbus organization has the documents describing the
protocol.  You have to do some looking for the older reference docs,
the newer ones primarily concentrate on Modbus/TCP.

You will also need the Micromotion document for the head you are
using.  There is a specific layout to the registers in the flowmeter.
 You will need that as well as the Modbus serial documents.

Other than facing a learning curve, I can tell you that interfacing to
Micromotion via Modbus works extremely well.

John Clymer


--- In AVR-Chat@yahoogroups.com, "babak" <babak1983ir@...> wrote:

>
> Hi,dears
> I want connect AVR(master) to micromotion flowmeter(slave).this 
> connection base on Rs485 plz help me for Modbus Protocol On AVR.
>