PIC18F and Profibus

[boboco]

Hi all,

I shall have to be concerning myself with Profibus implementation in the very new future and don't have much of a clue about it, except what I find in internet. Does anyone have expirience with eg. PIC18F4x8 (built-in ECAN) and Profibus, or can point a finger in the right direction?

I'm thinking of an implementation with selectable CAN2b or Profibus, as the manufacturer of the product I'm supposed to be inventing demands this flexibility.

A pleasent week-end to all,

Rob

[sougata]

Hi,

It would be better to know what are the exacting requirements. It would help to suggest. Go for the ECAN if you can. Microchip supports it actively.

[boboco]

Hi Sougata,

Thanks, I shall be using the PIC18F448 and am already implementing (E)CAN 2B as this PIC supports it, as you say. The customer however would like to have the Profibus at least 'D' as selectable option. His customers can use any one of the two standards and using a subD 9 pin connector for both systems is aceptable.

The idea is to build all units identically and allow the required selection, Profibus or CAN, to be programmed at commisioning. As far as I know at the moment, this ought to be possible.

Have a nice week-end,

Rob

[lab310]

A couple of times I had request for implementing Profibus in my devices. So far I wasn't able to do it in satisfying way. As far as I know, full documetation for Profibus cost arround 3000 euros, you are obligated to pay fee for using Profibus since it is a patent. This always turned me away for looking any further into this, and I used a workaround (use low cost PLC as gateaway). I'm very eager to add this "function" to my work, so please post any discoveries or toughts about this matter, it would be very appreciated.

Profibus speed starts at 1.5Mbps, but I think that slave devices can start as low as 9600 bps, am I right? Anything higher than 57600 would exclude PIC as possible Profibus slave.

[boboco]

Hello Lab310,

What you say tends to support my feelings about Profibus, about the cost is not so bad, my customer is a very large German concern and use Profibus world-wide.

I'll let you know when (if) I get on with it, until now not so easey.

Best Regards,

Rob