I am designing a new product based on a 8052 micro and part of the wish list is to support Modbus, canBus, DeviceNet & Profibus protocols.

I understand the basics of the modbus and canbus protocols but can any one help me with the others, or is there any commercially available software libraries out there to do the job for me?

 

I understand the basics of the modbus and canbus protocols but can any one help me with the others, or is there any commercially available software libraries out there to do the job for me? Are you aware those protocols are not ones you can just simply send out a serial channel? Modbus is the only one, I believe. The others are bit-oriented and I don't think your 8052 processor has the power to bit-bang those protocols. I may be wrong.

Rufus

 

As Rufus mentioned, only Modbus will be a simple fit into a native 8052. There is lots of Modbus source code on the web, although probably none of it is as simple as you'd desire.

CAN and DeviceNet will (to be practical) require an external CAN chip and transceiver. But they can be as cheap as $1-2 each and can use SPI interface, which some 8052 now have. CANBus is the media (like Ethernet) and DeviceNet is a protocol on CAN (like Modbus or Ethernet/IP on Ethernet). DeviceNet is not complex - it can run in CPU with 4K of code and a few hundred bytes of RAM. But you'll need to pay ODVA for the very fat documents and a Vendor Id. How much and how complex of a slave you create is up to you.

(My personal prediction is RS-485, CAN, Ethernet, and some wireless yet-to-be-decided will be the most common "medias" in 5-10 years)

ProfiBus also "prefers" a special chip. Due to the fast token-bus nature of ProfiBus you probably could di it all yourself on an 8052 but you'd need a long time and MOST of the PCU power just to "tread-water" and keep up with the bus. I don't know how much a ProfiBus co-chip costs.

best regards
- LynnL, www.digi.com