uNetwork document

[wcallan]

hi, the uTaskerV1.3.doc/0.03 refers to a uNetwork document (page 16/24).  Where is this uNetwork document?  thanks, wilson

[mark]

Hi

I think that the document may be included in some packages in the documents folder, but not all (as I see when quickly checking). It is also missing on the documentation page so I have corrected this by adding it. Please see http://www.utasker.com/docs/documentation.html or directly: http://www.utasker.com/docs/uTasker/uNetwork.PDF

The uNetwork is quite low key in the project since it is a little complicated to set up distributed systems (also the majority of projects are based on single boards and so it is not really relevant) but it has now been successfully used for quite a long time in some (enclosed control) industrial projects so can certainly be very useful.

Personally I have only actually used it with the SAM7X processor (up to now) which has an advantage in the fact that the Ethernet controller can be programmed with multiple MAC addresses (up to 4 if I remember correctly) and so the hardware can have one MAC address for IP use and a second exclusively for the uNetwork protocol. This avoids having to work in promiscuous mode when serving IP and control functions at the same time.

There hasn't been any discussions about the protocol and its use up to now. Do you have a possible use for distributed system operation?

Regards

Mark

[wcallan]

Mark, thank you for the prompt reply.  I am thinking about uNetwork on the MCF52234, but the catch is that one node will have to be on a linux machine (intel processor).  I would like the linux machine to be able to discover the 52234 nodes using the global message.  I see a potential problem with your 0x754e protocol type so i need to check if linux bind will be able to work with that, as opposed to UDP.

Any thoughts on this architecture?

Also, just as a comment, the uNetwork document is a bit confusing because the Ethereal screen captures show protocol type 0x5555.   

Thanks, wilson

[mark]

Hi Wilson

I don't know about the Linux possibilities, but the protocol was designed without the capabilities of PCs in mind (just a closed network of controllers with standard Ethernet capabilities). I suspect that it is possible but I wouldn't know what is necessary on the PC and whether this is then the best method or not.

Thanks for the note about the screen shots. The protocol type is configurable and I found that it was easier to work with a type which shows up clearly in Wireshark/Ethereal, which doesn't know the protocol. The 0x75e4 shows up as "uN" and so is easy to distinguish also in the raw binary. This change was made after the screen shots so I will need to update these.

Since the operation has been reliable in the projects that I am involved with I haven't actually had much need to capture the network activity. If I was using it more together with Wireshark I would consider trying to add an interpreter for the protocol content but, due to lack of experience with the way to do this, it has just been a distant idea up to now...

Regards

Mark