Open DMX to control RGB LED lights

[Serdj]

I solved my problem. I had to use the FT_SetBreakOn and imidately afterwards to use the FT_SetBreakOff function, before I use the write function. So basically, all I had to do is to force LOW signal for more than 88µs (in my case it is like 2ms). If anybody needs more help or a VI, contact me.

[Trinity32244]

I am currently looking for a way to use DMX to control a lighting system.  Unfortunetly I am very poor with networking and communications so any information you may have that will help me get off of the ground would be extremely helpful.  

[Serdj]

Hello Trinity,

I will help you, but i need more informations. Do you have a USB-to-DMX converter with a FTDI chip? If not, how do you plan to connet your PC to the DMX system?

[Trinity32244]

I prefer to use the on board RS485 with no converters.  My systems are in highly industrial environments and noise is usually an issue (USB and USB converters are usually a problem).  When I look at the specs for DMX-512 it seems to be RS485 on the transport layer anyway and uses a packeting system in a uni-directional communication method?  I am more or less wondering if it is not going to be to difficult to just use the VISA functions to assemble and send the information over a RS485 port.  Since the communication is uni-directional then I was thinking that it may be pretty straight forward to just assemble the information and send over the RS485.  As I stated before I do not know much about communications and networking so sorry if my thinking is way off base.  Thanks for any advice in advance.

[Serdj]

Hello Trinity,

yeah I think you can use RS485 connection port. I think my USB-to-DMX converter (FTDI chip) is also RS485. Can you make any kind of connection to your DMX system so that something happens?  Are you able to use any kind of commercial software (like freestyaler) in order to controll your DMX system? If you have an oscilloscope, than u can see the signals your sending.

U need to setup your RS485 to:

- 8 databits

- no parity

- 2 stop bits

- no flow control

I dont know exactly how you do it with VISA since I am also not very familiar with networking over LabVIEW, but this shouldnt be a big problem.

Then you send your 512 bytes (you can also send less bytes) and the DMX will accept them. Before you send now the next 512 bytes, you must put your connection for more than 88µs to LOW signal. After the "pause" you are allowed to send new bytes again.

Your first goal is to enably the DMX system to do at least something. In my case I was trying so long till some of my LED-lights turned on. Then I knew that at least my connectio is working.

[emann]

Hello,

can you help me and send me the vi? I tried it hours to controll my Dimmerpack through my Enttec DMXUSB PRO .. but without success. 

best wishes

 Erik

[Serdj]

I helped one guy through private messages. Here is his VI as a pic. He only forgot to enter the amount of bytes to write in the FT_write_buffer (far right in the pic). Let me know if it helped you!

Remark: You can delete the frame with the timedelay of 88µs (since the FT_SetBreakOn and FT_SetBreakOff need more time than that).

[emann]

Hello Serdj,

thank you very much for your help.

I did it as you told me, but the dimmer behind the USBDMX interface does nothing.

Status of the FT are all ok. (I attached the pic of the frontpanel)

Here is my vi.

best regards

  Erik

Labview 2011

[Serdj]

Try sending 512 Bytes (or maybe 511 Bytes) and not only 33 Bytes. Attach a pic of the control panel - dont have LabVIEW here at work 😄

[emann]

Hello Serdj,

here is the pic.  Same results also with 511Bytes.

I put the whole thing in a loop, but the here also the green LED status indicator of the Enttec DMXPro is not blinking.

I have one programcode in Visual C++ that works, but i don't know how to build a dll-file from that to use it in Labview.

best regards

  Erik