Mark Scoville wrote:

>>Stephen D. Barnes
>>
>>Thank you for the info! This is the starting point I was looking for.
>>Any pointers to anything already done? I would be interested in examples
>>to study if they are available.
>>
>>    
>>
>
>I don't know of any examples, but I haven't looked for 6 years! I can't
>share my code since it is work stuff :-(
>
>One thing you will probably want to get your hands on is a copy of ModScan.
>This is a handy little program that helps a lot with testing ModBus slave
>devices.
>
>When I did my initial implementation about 6 years ago (wow is it that old)
>I used a 16C73B @ 20Mhz (I think). The first step was getting the PIC to
>talk to ModScan using RS232. Next step was to add a RS-485 driver chip (and
>tx/rx control) and talk to some real Industrial SCADA stuff.
>
>Dig in and have fun.
>
>-- Mark
>
>
>
>  
>
I've been looking around the net and found a few ideas. I will take your 
advice and learn the protocol for both master and slave then take it 
from there. BTW, is modscan freely available?

-- 
Regards,
Stephen D. Barnes

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