CBus over ether link

Hey guys,

I am sure this would have been asked before but cant find anything currently.

But I am trying to find a way of connecting 2 C-Bus segments (of the same network) together over ethernet. If 2 PCIs back to back would pass commands between each other it would be fine, but like the CNI they don't. Has anyone done anything like this before? Or have any ideas?

Much thanks!

JB

 

I am interested in forming an engineering group to see if we can make it work over fibre optic.

 

Fibre

I thaught fiber would be the easiest one (it would not be using ethernet)

Just take a bridge replace the OPTO isolators with Fibre TX and RX

or it it not that simple.

Charles

 

The word Ethernet and Fibre are two different things. As you pointed out. You can in fact package serial over fibre rather nicely.

As far as I can tell it could be done with some existing fibre interface boards and about 1GB of buffer and 2GB of flash ram with a generic high efficiency processor.

Many years ago when I did the same thing for MOST in cars, we opted to use the processor that was double the price because at the required clock speed it had no heat sink requirements. Though we used a CPU with an OS.

I think 90% of the problem with hardware is that we have forgotten more than we have acquired. Some of the old single board solutions used by Data General and DEC still whip anything in circulation today.

The same can be done with a controller as used in the touch screens.

 

Upcoming Wiser 2?

How about the possibility of CIS including support for a C-Bus -- Ethernet -- C-Bus connection in the rumoured upcoming "Wiser 2"? (See halfway down the page on the following forum: http://www.cbusforums.com/forums/showthread.php?t=7390&page=3 )

Incidentally, does anyone have any further details on the Wiser 2?

 

This has been discussed previously and if I remember correctly there was no product out there that could do what is being asked.

To keep it simple, I would like to see the CNI have a mode [Ethernet Bridge - EB] that allows bridging of two C-bus networks (same network address). This would mean that there is no re-tooling involved, only firmware.

The Wiser 2 would be an overkill. Could you imagine installing two of them just to get an "Ethernet Bridge". Having it support the option and being able to be used with a CNI in EB mode would be more suitable, but that means that the CNI EB model would still need to exist.

Who is the sales rep for the Illawarra Area? If we need to tell them to give Clipsal the message then I will send him an e-mail.

Mick

 

I second Mick's suggestion but I would rather suggest the capability in both the CNI and Bridge (5500NB). Have your CNI talk Ethernet to a Bridge which would be a bit cheaper than two CNI's.

Call the new Bridge the 5500NBE

Ingo

 

Thanks for the replies, I might have to talk to Clipsal too as I think I could sell 20 'ethernet bridges' right now. With more I am sure in the future, I am a little surprised that something hasn't been made yet to do this as almost all other systems have methods of communicating over TCP/IP.

Something that may get me out of strife but don't have the stuff to lab it at the moment, but can a CTC connect to a CNI? Via ether? So similar to S-Plus but that way I don't need a whole PC to do any logic translations.

 

After having a few coffees and thinking about it. They could basically pipe the information through two WISER units with a tunnel between the two.

It would really demand a lot from the WISER though. It would have to be able to interpret similar code strings from two different nodes. Therefore it make it simple, the first rendition would still be limited to 256 units combined total.

Once an overlay or encapsulation was developed you could do 256 x N. At this point we are really taking about real-time processing and regimented setups and designs. It starts to get hairy once you tip the scales at 3 networks.

For example. If you do a broadcast packet to all 3 networks. It has to be detained, confirmed and synchronised. So how long do you want to wait for that ? I think 1500 milliseconds would confuse most people and they would be switching things on as soon as they went off, thinking it wasnt responding.

So you need a new kind of DLT and Touch Screen confirmation. Doing it on a normal wall plate would be "hilarious".

 

How about a Proof-of-Concept between two CTC's by writing a software 'Tunnel' interface and then just bridge the broadcasts to the Tunnel and local Cbus port. If it works then just add it to the CTC as a new feature to connect one remote network, anything more and you need H/W as it will get tricky as tobex mentioned.

Ingo

 

Would you need this to support all C-Bus applications or would just lighting (and lighting compatible) applications be adequate ? i.e. Basically a bridged application between the IP connected networks

K

 

If you look back at the first Level 3 switching hubs from Cisco you find that in order to manage that kind of traffic the bridging node would need to have the ability to store several lookup tables of the hardware addressing after a short learning phase.

There is no bit limit on the tunnel itself so if you like you may address things in 48 bits. But within those data segments, you would need to know everything about all networks.

 

I do remember many many years ago Clipsal did make a special that was a network bridge cut in half with a rs232 connection.
One job I worked on had 2 of these half bridges that were connected to a pair of rs232 wireless modems, worked great.
I wonder if Clipsal can still make these units?
Rossco

 

There is no reason why a matched pair of optical fibre units couldn't do the same thing.

 

or a higher quality serial to ether converter that has some more smarts than the CNI...

Having a meeting tomorrow I might see if we can chase Clipsal up about something like that....

 

Hi Rossco,
This was a once-off special and it's not an experience we're in a hurry to repeat. Ashleigh is right, the correct approach is to make noise to the sales folks that you want something like this as a standard product or feature.

 

has any one found a fix to this yet

 

If not afraid of hardware mods...

How about a couple of small units where a 5000SM/2 is hooked to a small Ethernet capable micro (say something like a PIC32MX695). Then stick one on each C-Bus network with the Ethernet in the middle. A bit of hardware and software required of course, but not that bad ;-)