Unit i.d. #'s

[Brad Ford]

Just curious and I apologize if this question has been asked several times over but I was wondering, why does LOR have so many strange unit I.D. #'s for the controllers?   Why not just number them in sequential order?  

[Don]

Just curious and I apologize if this question has been asked several times over but I was wondering, why does LOR have so many strange unit I.D. #'s for the controllers? Why not just number them in sequential order?

The strange unit ID numbers that you see are actually hex and not the normal numbering system that we as humans are used to.

As to why hex and not regular numbers it was programmers who wrote LOR.

[dgrant]

The Unit ID's are in a hexidecimal format which is part of how the data is transmitted via the RS485 network. RS485 allows for 64 devices on one BUSS when talking about usual RS485 devices therefore this form of addressing comes into play. I'll venture a guess that you might not know what hexidecimal addressing is and pardon me if you do.

 

0, 1's only, Base 2 or Binary

0, 1, 2, 3, 4, 5, 6, 7 Base 8 or Octal

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F Base 16 or Hexidecimal

 

When a command is sent to a particular controller, its header has the addresses programmed in, in hex unit number and channel number, so the receiving controllers know whether to pay attention or not. So if you send a command to Unit 1, channel 1, that first controller with matching ID will pick that up, wake up and say "Hey" he's talking to me and I need to do something with the information being supplied. But if its Unit 2, channel 1, then Unit 1 looks and says, "nope, not me this time" and ignores it. Does that make sense? As I said, RS485 communications can have 64 devices on one buss even though none of us would dare hang 64 controllers on one buss. We could, make no mistake, but it would be so slow that it wouldn't work out well at all.

[Don]

Very good explanation! 

[Brad Ford]

No problem.  No I don't really know what hexadecimal addressing is but what you explained makes a lot of sense.   I know how controllers "look" for the signals being sent out over the network and I understand that.  The addressing system I'm a little fuzzy on but its ok too.  I don't know exactly how the tv remote works but I know how to make it do what I want it to do.  The same thing for LOR...haha.  I'll keep putting on my shows and doing what I know how to do.   Oh, and as for the "off season" I'll stick to what I do know best....building and driving racecars hehe.  (which I'm sad to say is only marginally more than what I know about LOR)   hehehe.......thanks for the input tho!!

[dgrant]

I don't know a lot about race cars and wish I did, other than the Corvette's I've owned and one I have...never on a track though, so far. As for the addressing in communications, all comm needs to know where its going too or coming from, therefore there's addressing involved. Be it binary, TCPIP, GPIB/HPIB or even old RS232 and RS485 and others!!! Now how LOR is sending those commands, serially or in serial data packets to one device at a time, I simply don't know. Its whatever is most efficient for us. To put it into perspective, lets say there's 10 AC controllers only for the sake of numbers.  16 channels on each, therefore 160 commands that must be commanded out to the devices at warp speed so that us users don't see any lag or delay and considering we might be making changes in .05 second intervals or 20 times a second, times 160 channels or 3200 sets of commands per second which will include the address header and command for each channel or group of channels. Most of us are not changing that much so I'm sure that LOR has some selection process of what was last sent as opposed to changes, therefore saving data transmission but truly I don't know. This is why we have to pay attention to baud rates, good cable connections, noise and so on.

[dgrant]

Very good explanation! 

Thank You Don, Coming from you, that means a lot too me

[Mega Arch]

I wondered the same thing on unit id numbers.

Now we know. Thanks for the clarification.

Brad,

Is racing a sport?

Just curious.

[Brad Ford]

Lol some would say it's not, but it takes a lot more physical activity than the layman knows. I once ran a hundred lap race (which is a lot for the ole Saturday night dirt car) and by the time it was over I had lost 6lbs. It was a workout to be sure lol. It also takes lots of hand, eye, foot coordination. Your constantly making decisions on where to go when to go and how fast you get there. In this type of racing sometimes slower is faster. All this while you have to maintain vigilance on all the other cars on the track and be able to react to what they do. And that's not even scratching the surface of what kind of intelligence it takes. Anyone can drive a car around a track, but it takes something else to be able to drive it quick and finish consistently in the top. But to answer your question, yes, I believe it is a sport. Lol. Didn't mean to get long winded.Lol

[Mega Arch]

I respect what you do to prepare and to compete. It seems every year our work has this discussion/debate. I don't know if the guys ever actually finish and come to a mutual conclusion, but it keeps them off the streets.

[dgrant]

I've got the fast car but I've long known and respect, to drive a car at those speeds/conditions, you need professional training, experience and $10,000 set of brakes! More so in that everything in the vehicle needs to be in perfect condition to operate properly. On the top of the list of requirements is the brains behind the wheels. If it doesn't know everything, rested, fed, trained or learned properly...its a deathtrap for him/herself and others on the track.

[Brad Ford]

Very well said!  And thank you Mega Arch!