Auto DMX Addressing via RDM ?!

[chamber]

hi ...

I'm a freshman in DMX512 application field.
i had post a demonstration kit message :

http://doityourselfchristmas.com/for...ead.php?t=3848

I'm trying to add a auto-addressing to DMX512 as above demo kit.

I purchased the RDM draft document from office web and studied

the materials of RDM again, again.....

Is it possible to implement "auto-addressing" using RDM ?!

Have a real example be existed, now ?!...

Or, maybe anyone can give me comments or guideline....

thank you !

Chamber Ling from Taiwan

[sblair]

Chamber,

Yes it is very possible to implement Auto-Addressing for DMX devices using RDM.

The first requirement is that the device actually supports RDM so that it can be discovered and have the address set for it.

In a nutshell it would work like this:

1. Discover the devices.
2. Send a GET_COMMAND : DEVICE_INFO. In the response for that message it will tell you how many DMX channels that device needs.
3. Send a SET_COMMAND : DMX_START_ADDRESS to set the DMX Starting Address value.
4. Since you know how many channels that device uses, you now know the next available Starting Address for the next device.

Scott

[chamber]

Scott :

Thank you !

I will try it as soon as possible !

CHamber Ling

[chamber]

Originally Posted by sblair

Chamber,

Yes it is very possible to implement Auto-Addressing for DMX devices using RDM.

The first requirement is that the device actually supports RDM so that it can be discovered and have the address set for it.

In a nutshell it would work like this:

1. Discover the devices.
2. Send a GET_COMMAND : DEVICE_INFO. In the response for that message it will tell you how many DMX channels that device needs.
3. Send a SET_COMMAND : DMX_START_ADDRESS to set the DMX Starting Address value.
4. Since you know how many channels that device uses, you now know the next available Starting Address for the next device.

Scott

Scott :

How should I define which device located at the first position ?!
Using RDM discover process, I can find how many devices be connected, and how many channels that device uses...
For example, the video as shown below, I used 11 DMX512 LED devices and uses 4 channels for every device.
If after I arrange the alphabetical order, do you think that is possible for
keeping the NEON program when I re-initialize the all of DMX device starting address using the discover the all device again ?!

http://www.youtube.com/watch?v=APQDnxl6aoM

sorry for my broken english !

I hoped that you can understand my question key point !

Thank you !

Chamber

[sblair]

Chamber,

I'm not sure I understand your question. I'm not sure of what the NEON program is or does that you mentioned.

Scott

[chamber]

Originally Posted by sblair

Chamber,

I'm not sure I understand your question. I'm not sure of what the NEON program is or does that you mentioned.

Scott

OK...

I will try my best to explain this question.
For exmaple :

At first, I already finish the arrangement of letters in this video by hand:

"T" -- DMX device starting address : 1
"e" -- DMX device starting address : 5
"x" -- DMX device starting address : 9
"a" -- DMX device starting address : 13
"s" -- DMX device starting address : 17
.....
Second, I change the sequence of letters :
"T"
"x"
"s"
"a"
"e"
...
Finally, How should I find the new DMX device starting address using "RDM discovery" as below ?

"T" -- DMX device starting address : 1
"x" -- DMX device starting address : 5
"s" -- DMX device starting address : 9
"a" -- DMX device starting address : 13
"e" -- DMX device starting address : 17


I hope you can realize my meaning.

Thank you !

[sblair]

It still isn't completely clear.

Does each letter have it's own DMX/RDM input integrated or do you have a dimmer/relay that is DMX/Controlled that each letter plugs into?

In the example of a dimmer rack, when you discover it you are discovering the dimmer itself, not the fixture that is plugged into the dimmer.

What is the relationship between the LED letters and the DMX/RDM Receiver?

When you discover a device in RDM, you are discovering it's Unique ID number which is a 48-bit number that has 32-bits of your own serial number. You also have Product ID and other identifier fields that you could use to encode the information of which letter is which. If however, there is not a constant 1-1 relationship between them then you don't know which letter is connected to which DMX/RDM Receiver without someone visually identifying and assigning using the IDENTIFY message.

[mike_k]

If I understand correct you want auto adressing to be done so that the devices with the letters are adressed in the order that they are located physically? For instance the order that the are connected on the RDM/DMX line?

[chamber]

Yes... Mike got it !
...
Said by mine meaning:
Every letter's DMX controller have its own unique ID and its "default" DMX starting address when it leaving the plant !
When the end user choice the letters what he/she want. Maybe three letters, or four
letters and so on...
Of course, In this time, the DMX console does not know which letters is this character is composed of .
If the letters joins one by one, the DMX console may discover the every the device of letter, and "re-define"(changes) the starting address one by one.
...
My question is... When all of the letters join in one time. Every "default" starting address should be changed together based on the order of letters location.
The Discovery method did have not mention this order problem. is it not ?!
Or, How should I do ?!
..
Thank you !

Chamber

[chamber]

Scott :

I was just careful see the "DMX/RDM" releated market discussion:

http://www.rdmprotocol.org/forums/showthread.php?t=1000

I also completely agree with your viewpoint.

I focus my job on the simply and easy LED console and controller implemention.

Let us together diligently!

[mike_k]

Are you developing your own LEDfixture as well as the controller?

In that case you have good possibilities to achieve what you want.

First of all, RDM is not topology aware. The controller have no (or at least very little) possibility to know the order of the connected devices on the daisy chain RS485 link.

I see two ways forward:
1. The user have to plug in one letter at a time letting the controller discover it and then set the adress of it and indicate that next letter could be connected (for instance by light the letter in a certain colour).

2. Make sure that the LED fixture do not expose the next device for DISC_UNIQUE_BRANCH messages until itself have been successfully discovered and muted.

[chamber]

Thank you for reply soon. Mike.

My PC software application system (USB2DMX) provide the configuration address of DMX device.

Your meaning that it should ask user to "enable" controller by hand to discover the new letter and set address of it, is so ?!

Therefore, my idea is : Uses the Discovery method on the PC Software, lists all of devices and try to control one device at one time.(for instance by light the letter in a certain colour). It is possible to arrange their order easily !

That was still rest on the RDM !

Thanks everybody's opinion discussion.

[sblair]

Chamber,

Now that we are all on the same page here. As Mike mentioned RDM is not topology aware so it will discover all the devices out there in whatever order the discovery process finds them in.

The IDENTIFY_DEVICE message (Section 10.11.1) is meant for you to issue a command that allows the user to visually identify which device it is and then set the DMX Address or any other configuration parameters for that device as appropriate.

So when you get an IDENTIFY_DEVICE with the Identify State set to ON, then you would strobe that letter for example and then the user could assign the right DMX Address or associate with which ever letter/device you want in your application and then it could automatically set the DMX Address.