LON Question

[sysint]

Some "big-time" fitter on this site needs a little help with a question I asked:

Originally posted by XXX XXXX
... I am yet to meet my equal in this business,and when I do I will acknowledge it.

What the heck... I'll give it a whirl...
How many message slots in a LON network (FT10)?[/QUOTE]

I would think there are a bunch of guys that can answer this fairly quickly. I can say the following is an incorrect approach:

I am waiting for you to correct your question, I thought if I left it unanswered for a while you would realise that calling something an FT10 does not narrow it down to one part, FT10 is not a part, Now which part are we talking about ?

[crab master]

I may be a litte confused on what you are asking exactly here, but what the heck I'll too give it a whirl. TP/FT - 10 is the wiring/transciever type used for your channel to your devices which is twisted pair free topology unshielded wire - for the guy that seems to know it all.

Now message slots or priority slots? Priority slots the max is 4 by default for tp/ft - 10. Not sure on message slots.

[Edited by crab master on 04-07-2005 at 03:39 AM]

[jimmyj]

16.

[sysint]

Crab's already headed the right direction... JJ- where did you pull "16" from?

I'm surprised that a guy who thinks his b@$$s are sooo big to post this on H-talk:

Originally posted by XXX XXXX
... I am yet to meet my equal in this business,and when I do I will acknowledge it.

......doesn't have even a clue and Crab Master within 24 hours is on track. Wonder why that is?

[Edited by sysint on 04-07-2005 at 08:10 AM]

[muswell_hillbilly]

1 - 63 based on traffic load?

[sysint]

In Lonworks as network "traffic" increases the network dynamically increases the number of message slots. The number of slots is not static.

In addition there is also priority message slots when a message absolutely has to get transferred.

This is different then Ethernet which simply loads up and crashes.

That's the elegant feature of a Lonworks network some "big-time in his own mind" fitter posting here didn't know.

Originally posted by fat eddy
... I am yet to meet my equal in this business,and when I do I will acknowledge it.

Originally posted by fat eddy
Now do I know everything about lon networks and devices, NO I don't but I assure you that I have more exoerience with them than either one of you guys.

NICE. Thanks Guys. Notice we got another WI guy posting... why he calls himself a hillbilly I don't know...

[muswell_hillbilly]

A bit hasty in my last reply - I believe there are a minimum of 16 slots, multiplied by a scale factor from 1-63, depending on network traffic. So number of slots ranges dynamically from 16 - 1008?

[lonboy]

Hey, great thread Sys. I work with this stuff everyday and I learn something new everyday!
Another cool thing about LonTalk over FT10 is that each packet sent contains the expected number of packets in it's transaction. So, all the devices on the channel use this info to calculate the backlog (how busy the channel is) and randomly adjust their media access time slots to reduce the probability of 2 devices sending at the same time. I think it's called P-Persistent CSMA (Carrier Sense Multiple Access)protocol. And, you can assign a specific time slot to a device - Channel Priority. It's like having your own car pool lane and nobody can drive in it but you. But, this can negatively affect all the rest of traffic - who cares you say! Priority is best implemented for critical devices operating on a channel operating with high traffic. Plus, routers have priority buffers that always forward priority packets first.

I hear the new LonScanner protocol analyzer (LSPA) is soon to be released which will show you a live packet log and includes statistics, error rates, filter options, and more! It will sell somewhere around $500 - much less than Loytec and with more features. Also, Echelon probably won't sell very many new PCC-10 cards as the USB interface is out any day!

Have a good one!
lb

[fat eddy]

So nobody really knows ?

[lonboy]

The answer to your question is zero. There are no 'message slots' in a LonWorks network.

Now, here's one for you Big Ed, how many subnets can you have on a channel?

lb

[sysint]

I hear the new LonScanner protocol analyzer (LSPA) is soon to be released which will show you a live packet log and includes statistics, error rates, filter options, and more! It will sell somewhere around $500 - much less than Loytec and with more features. Also, Echelon probably won't sell very many new PCC-10 cards as the USB interface is out any day!

Hey, that's kinda advertising.... Loytec has some good stuff too.... USB about time!!!

Where's the ilon2000? It's late. You guys don't know JACK.

You should see our new demo... you would like it.

[fat eddy]

Ok thats one for Eddy,

Originally posted by lonboy
The answer to your question is zero. There are no 'message slots' in a LonWorks network.

Now, here's one for you Big Ed, how many subnets can you have on a channel?

lb

[sysint]

BTW, I had to phrase the question so the wing-nut couldn't just "google" it.... I just think that the way Lonworks increases/decreases according to network traffic is awesome...... and you still have priority message (randomization) slots.

Can you say "stop that train"?

The hillbilly is all over it... Max 127 time slots priority and 1008 standard time slots. And dynamic!

In the message header is information to help the network ramp up to handle the traffic. Elegant.

Slightly off.... I just had a meeting today with a spec engineer. He was so BACnet ingrained he just could not accept the interoperability of Lonworks. (this is 2005)

[Edited by sysint on 04-07-2005 at 08:41 PM]