puffinbus ideas


Thread Starter

Ken Emmons

First of all, I would like to compliment everyone involved in this project for their innovative ideas and contributions to "the cause".
(Open source, and linux, etc.) Having said that ..... :eek:)

I have been lurking around the list for a while and I am quite disturbed by the threads I have read concerning the puffinbus ideas.

There are only a few busses to consider. Period.

Profibus, ethernet, and Devicenet.

If you want speed you go to profibus. If you want simple and robust you go to Devicenet. Ethernet is still a little bit bastardized and I am not
even sure if the industrial IO standard is stable yet.

I have designed a hardware/software system based on the SDS protocol proposed by Honeywell. SDS is for all intents and purposes Devicenet's orphaned twin (It is based on CAN). The CAN Hardware is so readily available that today you can plug in a microcontroller and a transceiver chip and have a network device (OK, so you have to wire 5V and ground and a few capacitors, etc. Whoopy!) . It is really this simple. Why invent your own?? You will end up with something like Devicenet ten
years later, except it will still be lacking.

DeviceNet is, BTW, a REAL OPEN standard. That is why you pay for the specs, so people will continue to enforce the standard and improve it.

BTW, Puffin PLC NEEDS to support Generic memory mapped devices. These are the Basis for most IO cards. My favorite is the IP (Industry pack)
standard dominated by SBS-Greenspring computers. It is open, widespread, and good. I currently have a machine running at work with two 48 bit
digital IO IP modules in it (you can get 6 IP sites on a single PCI card or 4 on a ISA...)

I hope this has helped, and that I have not misinterpreted the PuffinBus discussion threads. I am kind of new to this kind of NewsGroup
discussion method, and it is quite possible that I am responding to old information.


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The idea behind having a puffinbus is definitely a very good one. That will be the equivalent of "Linux" in a world of so called open and standard OS's. The different standards like profibus, CAN , devicenet etc are actually not as freely accessible to us (india). Therefore a truly open standard with GPL etc will be most welcome. venkateasshwar