LOR +1 channel frustration

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mmkooiman67

New elf
Joined
Jan 13, 2012
Messages
17
Hello All,
This is my 7th year with LOR but my first year with DMX. I bought 30 of those small 3 channel contollers to control a bunch of RGB strips. I used the Holiday Coro programmer to set the start addresses. I assembled all my control boxes(controller,power supply,etc). Now I am testing and I am having all kinds of issues. I have some controllers, but not all, that are flickering on fades, but not on solid colors. But my biggest quondry is some of the controllers I have to do a +1 on the start channel and others I don't. This wouldn't be a big deal but I have three controllers that are supposed to be channels 4-6, and one works like that and the other two are 5-7. I am using the LOR usb45 dongle and version 3.4. Any help would be greatly appreciated. Thanks in advance,
Mark
 
I have a feeling you may not be the only one having issues with these mini controllers and flickering.

First of all at the end of the data line you must install a 120 Ohm terminating resistor to minimise any generated reflecting signals within the DMX data line. The issue with these cheap holiday coro controllers is that there is no physical DMX out, so instead you are tapping off the DMX signal instead of daisy chaining. The length of the data line between the controller and the DMX main line must be as short as possible to minimise generating a reflecting signal.

The other issue with using this many controllers on the same network is that all it takes is one dodgy connection, controller or power supply and this will also cause your flicker, so this can only be found by a process of elimination and the more controllers and connections the higher chance for something going wrong.

Now the issue you mention about the +1 start address is a well documented issue over at the LOR forums regarding the use of the LOR dongle as an open DMX dongle. So dont think much can be done there, maybe have a search of the LOR forums which may yield more info on the issue.

Hope that helps in some way.
 
Thanks for the reply Eddie,
I do have the 120ohm resister in place, guess I just have to chip at it until I figure it out.
 
mmkooiman67 said:
I am using the LOR usb45 dongle
Click to expand...


Particularly with the 3-channel DMX controllers, the USB485 dongles were almost always +1 for me. This was reported way back during LOR's beta testing of DMX. The problem is not the LOR software and can't be dependably fixed in software.


The problem is that the "break" signal sent by that dongle (and the D-Light dongle, too) is not "up to Spec," so many controllers miscount the channels, either starting late or early.


The only fix is to get a better dongle. LOR S3 supports so many, now. My first option last year was to buy an ENTTEC Open (without a case because it is cheaper). I desoldered the round DMX plug and put an RJ45 jack in its place. Cheap and flawless. The Pro dongles are better from a CPU usage standpoint, but for a single universe setup, it makes little difference.


The latest version of LOR S3 Advanced supports E1.31 and that is the best setup for smooth displays. (my opinion, anyway)
 
Any of the "open style" DMX dongles should behave exactly the same as far as the timing is concerned as that's controlled by the PC software.

The Enttec DMX Open uses a slightly different chip to the LOR one (and mine) but in both cases the timing is still controlled by the PC.

The real issue most of the time is the firmware in the DMX controllers. This has been an issue since the early days of cheap Chinese DMX gear. Not all Chinese equipment has issues though of course.

The firmware in my controllers seems to be pretty tolerant of the timing variations so I've not noticed any problems with shifted channels.
 
The break signal is actually to spec. The difference is that the break signal is at the minimum setting that is specified (8uS for the make after break from memory). Most other software uses a much longer break time which is allowable in the spec. I'm aware of this problem as I developed the same problem with my AahMega60 board. Everything seemed right with the code and the signal and it was only by doing a side by side comparison I could see the marked difference in the break signal.
 
I purchased an Enntec open and no more problems. Thanks for all the great info!
 
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