PixelNet - VB Programming

[TexasStingray]

If this is to technical for the BB I would be glad to send a PM but I did not want to bother the BIG GUY. I'm sure he gets enough PM's. So here go. I have read what I could on the wiki about PixelNet being 4096 Channels and that the Plug-in for Vixen converts any channel that has a value of 170 to 171, and that if you are mixing DMX (Lynx Express say channel 1 - 16) and SS from 17-4096. Signal that is sent the same for only 512. In other words if someone had an USB Dongel, Flashed for PixelNet, Could the program written for 512 channels be used for PixelNet Smart String, or does the signal have to be 4096 bytes.

Thanks
Scott

[tbone321]

Pixelnet and DMX are two different protocols.  If the dongle is flashed for pixelnet and you want to use a DMX device, then you would need to either use another dongle flashed for DMX or use the DMX output port on an active hub.  It is more than just the channel count that is different about them.

[TexasStingray]

Yea, I get that. What I want to know is the signal being sent to the Dongle the same just 4096 bytes vs 512 bytes. Is the  dongle is doing the converions?

[tbone321]

Yes, the dongle is doing the conversion. 

[TexasStingray]

1). But does the signal have to be 4096 Bytes?
2). If not, Can I use a program that was working with the Lynx USB Dongle Flash for DMX, If I reflashed it for PixelNet as long as I did not have any 170 values in the channels? I know it would be limited to 512 channels.

[chrisatpsu]

i believe that vixen only sends updates to the dongle, and the dongle sends a steady stream to the equipment

[rrowan]

1). But does the signal have to be 4096 Bytes?
2). If not, Can I use a program that was working with the Lynx USB Dongle Flash for DMX, If I reflashed it for PixelNet as long as I did not have any 170 values in the channels? I know it would be limited to 512 channels.

When I wrote Color Finder I found it was more stable sending out 4096 bytes. I think the dongle was waiting for a certain size of data.
Just use two arrays, one for dmx and another for pixelnet and use a variable for the max channels in your loop.

Also the header changes with dmx and pixelnet with pixelnet header only being a 170 byte number.

btw: I am still looking for what is required to send data to the etherdongle.

Rick R.

[rokkett]

Here is some Perl code to show the differences between the DMX and PixelNet serial packets:

Code: You are not allowed to view links. Register or Login

#
# Assemble PixelNet packet
#
if ($Protocol eq 'PIXELNET') {
            $channel_data = chr(170) . $channel_data;
        }
#
# Assemble DMX packet
#
if ($Protocol eq 'DMX') {
            $channel_data = "\x7E\x06" . chr($length & 0xFF) . chr(($length >> 8) & 0xFF) . chr(0) . $channel_data . "\xE7";
        }
Notice the DMX packet has more header information and the trailing break byte.  PixelNet simply has the the leading chr(170) byte.

So, no, you can't just send a DMX stream to a PixelNet device or vice versa and have things work correctly.

rrowan - Yeah, I also noticed the 4096 byte anomaly.  Reading the specs, we should be sending the start byte followed by 4096 channels of data in bytes - 4097 bytes.  But the PixelNet dongle doesn't seem to like that - it wants just 4096 bytes.  I mentioned this before, but no one seemed to be aware of or had experienced it.  I think we are really limited to 4095 channels in a PixelNet Universe in the current dongle firmware as the 4096th byte can't be sent/received by the dongle.

Also, if you are interested in talking to the EtherDongle, catch up with me - I have both Java and C# code that generates E1.31 packets.  Both have worked successfully with the EtherDongle.  Check this out - a Vixen 3 E1.31 output module I wrote: You are not allowed to view links. Register or Login
   

[TexasStingray]

I also want  like to get it working with the ether dongle, i understand java more than i do C++. If you would be willinh to send it to me that would be great.

thanks Scott

[rrowan]

Hi rokkett,

C# will be fine. I'll send you a pm

Thanks

Rick R.