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http://www.artisticlicence.com/cat3_1.htm
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Hi,
not sure this is the right forum to ask, but there seems to be some activity around here, the artistic license forums are not so active it seems...
I have a very very very basic question about the ArtNet protocol:
I'm investigating the possibillity to programmatically control lights over ethernet using an artNet to dmx interface. I am new to dmx as well as artNet, so forgive this question:
in the ArtDmx specs I don't explicitly find the structure of the dmx data, I guess this is so straigthforward for all you dmx wizards that it seems ridiculous to explain ?
in my naivety I see two options-
option1:
it is a sequential list of dmx values, length 10 means values for the first 10 channels, length 300 means values for the first 300 channels, every value is one int8 in size
option2:
it is a list of channel - value combinations, like 100 20 101 20 102 20 would set channels 100-102 to value 20 but here I would not understand what the size of each 'field' would have to be.. since 512 doesn't fit in an int8..
thanks for your patience,
Joost.
rekveld at lumen dot nu
dmx data doesnt really have any 'structure'.Quote:
Originally Posted by rekveld
its extraordinarily simple. its not really what one understands by a protocol
option 1 is the way i use this.
Thanks for the reply to my previous question, it made it possible for me to make some Max patches to control ArtNet and program the stuff I wanted to do. I'm was working on a project to control multiled tiles from Max/Jitter on a Mac.
For two weeks now I've been in the possession of an Artistic License Ether-Lynx O/P interface, and well.. it's a bloody nightmare !!
I have tried everything to get it to work, but it won't, talked to many people, talked to the nice guys at artistic license, but so far no solution.
My time is running out now, I have a week before my show and I still haven't been abel to run any tests with actual lights on. I'm seriously considering to send back the unit and go for a less optimal solution (the LanBox from CDS in Holland, they are mac and even max/jitter-friendly), but which would give me less dmx-slots for the budget I have.
As a last attempt I want to describe my problem:
I power the unit, the led's do their chase thing, the red one is on.
I connect Ethernet, but the yellow one does not come on, whatever I try. I've tried all possible settings, powering up sequences, with crosscable, with a hub, etc.
At times (during a few minutes after power-up) my mac thinks there is a network, hubs tend to agree, but the unit apparently never thinks so...
After a couple of minutes the led's go back into their chase mode (if they ever got out of it in the first place).
It took me a while to discover that this means that the problem is probably not in the packets I send, but that it is more basic than that: there is even no network.
my understanding is the following:
computer settings:
IP: 10.0.0.1 (yes, I put the alt-net jumper in the unit, also tried 2.0.0.1 without the jumper)
subnet mask: 255.0.0.0
no DNS or router adresses
ethernet manually configured 10BaseT/UTP half-duplex, 1500 max packet size (also tried automatic configuration)
I use a cross-ethernet cable (or a hub, tried all other combinations too).
Power comes through the 4pin XLR, not the ethernet connector.
What on earth can be wrong with this ?
Is there a magic trick which suddenly will make it work ?
Is there a some subtle develish difference between ethernet on mac and pc ?
any (speedy) magic much appreciated.
regards,
Joost.
use an ethernet switch - not a hub.
A switch allows each network port to set its own speed.
and dont use a crossover cable.
I own 3 products from the Artistic Licence Range and have never had any problems. I created a separate profile in networking Called Artnet. In Network preferences On the TCP/IP tab I have configuration set to manual. An IP address of 2.0.0.134 Subnet of 255.255.255.0 and everything else blank. On the Ethernet tab Configure is set to automatic. I doubt it makes any difference but I also have person file sharing enabled. I then simply use a patch cable to connect between the Mac and the Etherlynx. The yellow light should come on immediately and the network will be established. This works on my G4's, G5's and Powerbook.Quote:
Originally Posted by samsc
i have had problems getting dmx input working, but never dmx output.Quote:
Originally Posted by rosswill
i use always use an ethernet switch as this gets rid of any auto-sensing problems between mac and artistic license box.
Macs auto sense both speed and sex of ethernet.
ether-lynx only works at 10BT.
thanks a lot guys, appreciate your help very much !
hope i didn't come across as being too negative about the artistic license unit: I know it's probably me who doesn't really know what he is doing, and I wouldn't have bought the unit in the first place if I didn't think it is a good product....
I tried the settings with IP 2.0.0.134 subnet 255.255.255.0 as described, did the same with jumper on and IP 10.0.0.134 same subnet.
tried straight cables, cross cable,
power unit first, mac afterwards and the reverse order
tried some variations of the above settings, also tried with my manual settings for the type of ethernet connection, but no luck at all !
I don't get it...
tomorrow I'll pick up an ethernet switch and give that a try, after that I am going to give up and go for an alternative, since my time is running out..
Very strange..
thanks again,
Joost.
im a fan of the ethernet switch with leds. then you can see whos talking...and whos not...
...final suggestion... try plugging direct without using a hub or switch. It might help you trace the fault.
i think something is wrong in his software.
this is my c struct for an artnet packet from their spec
typedef struct ONE_ARTNETDMX_PACKET
{
char ID[ 8 ];
unsigned short OpCode;
unsigned short ProtVer;
unsigned char Sequence;
unsigned char PhysicalPortIndex;
unsigned char Universe;
unsigned char UniverseHi; //docs says this is unused
unsigned short Length;
unsigned char Data[ 512 ];
};
well,
something wrong in my software, i wish I got to the point that I could find that one out..
I sent a sample max patch to the lanbox people in Rotterdam (www.lanbox.com), they had to fill in their header, ip and port, and it worked immediately with their ethernet box. No problem.
So I am positive that I'm sending proper utp out.
this limits it to two things:
A:
my header or ip settings are wrong. This is a documentation issue, has nothing to do with my software. I follow the specs, some of the advice I got (an tried) on this forum is different, especiialy the port and ip settings. I find the specs are not unambiguous. The header for an artnetdmx packet I use is this (list of char values in decimal, so shorts are split in hi and lo byte):
65 114 116 45 78 101 116 0
0 80
0 14
0 0
0 universe
lengthHi lengthLo
in the specs it says the bytes of the opcode are reversed (why would anyone do that ?), so I would be curious to see what the content of the 'opcode' field in your struct is.
B:
it is a hardware issue of some sort, faulty box (unlikely, true, but i start to doubt seriously) or some kind of ethernet incompatibilty I fail to understand.
ok, this is what happens with the switch:
1. ethernet switch on
2. arnet box on
3. plug in artnet box into switch: green light on switch comes on, no yellow light on artnet unit.
4. plug in mac into switch: green light on switch comes on, mac sees the network.
5. I send data: green light on switch for the artnet box dies. Nothing happens, leds go into chase mode.
my issues are:
- I will have to wait for at least an hour before I can try again: my experience is that if I just power the artnet box again, it will completly fail to respond to anything I send it. Only after a 'very cold' boot the switch (or the hub I used previously) will see the artnet box is there, I have never actually seen the artnet box with a yellow light on.
I don't know what couses this behaviour, it is not mentioned anywhere, and makes any sort of testing basically impossible. Why would any device behave in this way ?
- it is still not clear to me what the *exact* meaning of the yellow light is, Is it a light indicating the status of the network, like the green light next to ethernet port of my modem, which is always on, without blinking, OR is it a light indicating valid data traffic, like the activity lights on my hub and on my newly acquired switch ?
so: if it is not on, does that mean that no data whatsoever arrives, or does it mean that I send the wrong data ?
I am getting seriously annoyed at having to think about ethernet and about trivial headers, I want light !
I am going to give it another try (in an hour..) with an 'unreversed' opcode (i think i tried that already before), then I'm going to give up wasting my time on this thing and buy a lanbox.
[QUOTE=rekveld]well,
in the specs it says the bytes of the opcode are reversed (why would anyone do that ?), so I would be curious to see what the content of the 'opcode' field in your struct is.
QUOTE]
well the key to any documentation, is reading it very very closely and do exactly what your are told.
but even then documentation and ones interpretation can be incorrect.
'Reversed' opcodes would be a sign of a little endian vs big endian byte order. same as all pentium pcs.
are you sending to udp address 255.255.255.255 or 2.255.255.255?
Quote:
Originally Posted by samsc
well the key to any documentation, is reading it very very closely and do exactly what your are told.
but even then documentation and ones interpretation can be incorrect.
I sure tried to read as closely as I could and do exactly what I understood ! The fact that I wonder why anyone would like to reverse bytes did not stop me from doing so myself...
Quote:
Originally Posted by samsc
'Reversed' opcodes would be a sign of a little endian vs big endian byte order. same as all pentium pcs.
that bit of information is new to me, only did programming on mac (and atari, way back), don't normally come close to pentium machines, but that has nothing to do with that I followed the specs, it says for every field whether hi or lo byte is first, that is pretty clear, although I don't understand why a protocol would mix both representations..
I guess there must be some historical reasons of some sort, some hardware reasons.. ?
Quote:
Originally Posted by samsc
are you sending to udp address 255.255.255.255 or 2.255.255.255?
as listed in the specs (page 8) I send to 2.255.255.255 (or 10.255.255.255) with the jumper).
255.255.255.255 is pretty crazy, no ?
but what the about that first 8-char string, is that 'big endian' too ?
i accidentally pressed edit rather than quote. so your post got broken
i use 255.255.255.255...
its the broadcast ip address. removes one more thing to go wrong.
you might have to set the sub-net mask to 255.0.0.0 to use 2.255.255.255
though i dont know...
it is possible that your artnet box is broken.
i did two installs in the last week, and at both one of the new boxes was broken.....
strings dont have endian ordering.Quote:
Originally Posted by rekveld
but shorts and long integers do.
on powerpc the number 0x1234 in hex is arranged in memory as 0x12 0x34 but on pentium its order in memory is 0x34 0x12
bought two lanbox-lce's and it took me 10 minutes to get them working !
Finally, I think I deserved it, four days before my show..
anyway, thanks a lot for all your help and suggestions over the last few days.
Joost.
Do you lanboxes use UDP packets?Quote:
Originally Posted by rekveld
R
yes,
they recently upgraded to a new firmware for their boxes (it could even still be in beta), and the new firmware allows to write dmx directly into the 'mix' buffer of the lanbox. The udp packet is a list of dmx values, and a header containing an instruction code, the start adress and the length of the list.
This is how I used it yesterday, but these boxes can do much more: they are designed to be stand-alone controllers. I think with one lanbox-LCX and several lanbox-LCE's slaved to it you could even have a 'super-dmx-universe' of several thousand channels, the LCX keeping track of which channel should go to which box.
and I'm very happy to say that my installation yesterday worked just fine (and people liked it too..)
ciao,
Joost.
Hi,
I've been complaining about Artnet a lot in this thread, and it turned out that my box was faulty, after all. The Artistic License people repaired it and tested it nicely.
The box I bought is now for sale: I have never used except on my desk and haven't even connected it after I got it back from Artistic License last summer.
It is an Artistic License Ether-Lynx O/P interface, I'll take any reasonable offer, I'm based in Amsterdam so shipping is not enormous, but we might have to work something out for tax and stuff.
thanks,
Joost.