Lightronics AF-3007

[Les]

Does anyone know the communication protocol used between the Lightronics architectural fader stations and their dimmer cabinets? It appears to use one pair for Data +/-, one for Voltage +, and one as common/shield. From what I can tell, it's a proprietary signal used primarily/exclusively with their 1202 dimmers.

 

[DrewE]

According to the dimmer documentation I can find, it's a bidirectional RS-485 bus, operating at 62.5 kBaud, 9 bits (!), with apparently the dimmer acting as a master and the control station(s) as slaves in whatever (proprietary) protocol they use. Obviously this would have to be half-duplex operation since there's only one data pair.

I'd guess the ninth bit is probably either even or odd parity, but I might be wrong on that. Figuring out the protocol, assuming one can't find reasonable documentation on it, might not be too terribly difficult at least as far as it extends to simulating/replacing an existing remote station or something similar. It would presumably be even simpler, however, to just drive the dimmers via their DMX512 input if that's an option in your situation.

 

[Amiers]

I think it’s LMX. We have the consoles at the shop, they do have both LMX and DMX. I can check for sure tomorrow and see no reason why it would be different than the architectural panel.

 

[microstar]

I think it’s LMX. We have the consoles at the shop, they do have both LMX and DMX. I can check for sure tomorrow and see no reason why it would be different than the architectural panel.

The OP is talking about remote station to AR1202 dimmer cabinet communications, not lighting console to dimmer cabinet. The former is NOT LMX or DMX; it is a proprietary protocol, see below.
"Lightronics Architectural Network" bi-directional RS-485
@Les--were you having a specific problem with remote stations communicating with the AR-1202? The remote stations show up on eBay from time to time. Important to note that there is not complete interchangeability between different classes of their remote stations and that certain types of stations will only control certain ranges of scenes programmed into the AR1202 cabinet.

 

[Les]

were you having a specific problem with remote stations communicating with the AR-1202?

Actually, this is more of a crazy idea I had once I learned how easy it is to use a DMX or even analog station to control a string of LED tape. My goal is to build a scale model of my stage with installed LED tape and a small fader station to get good variation of color for lighting and scenic design concepts. It will be easier just to buy a small Elation board, but I saw one of these stations on eBay, which brought me here.

The knowledge is great otherwise though, if I ever encounter these stations in the wild.

 

[microstar]

Actually, this is more of a crazy idea I had once I learned how easy it is to use a DMX or even analog station to control a string of LED tape. My goal is to build a scale model of my stage with installed LED tape and a small fader station to get good variation of color for lighting and scenic design concepts. It will be easier just to buy a small Elation board, but I saw one of these stations on eBay, which brought me here.

The knowledge is great otherwise though, if I ever encounter these stations in the wild.

Interesting idea. Since I have several of the preset stations for service work, I once had the idea of buying a replacement AR1202 control pc board ("brain") for a neat DMX control system... until I figured out
the brain did not have a DMX output, only a DMX input. The outputs go to the power cubes..... duh.

 

[Les]

Haha. I've had similar brain farts. I have two analog stations - one 6-channel by EDI and an 8-channel from Lehigh. I'm trying to find new and interesting ways to put them to use. A Northlight analog-DMX converter and DMX-PWM decoder should let them control LED tape. It's kind of roundabout, but I'm curious to try it. Our theatre lobby has a ceiling cove of neon, which we would like to replace with LED (leaving the neon intact but removing the transformer(s). Simple slider stations for RGBA/W control would be preferable to keeping up with multiple battery powered remotes.

I wish I had more of the EDI fader stations. They seem really well built. I check eBay regularly, but equipment other than dimmer modules and full consoles rarely pops up.

 

[microstar]

Haha. I've had similar brain farts. I have two analog stations - one 6-channel by EDI and an 8-channel from Lehigh. I'm trying to find new and interesting ways to put them to use. A Northlight analog-DMX converter and DMX-PWM decoder should let them control LED tape. It's kind of roundabout, but I'm curious to try it. Our theatre lobby has a ceiling cove of neon, which we would like to replace with LED (leaving the neon intact but removing the transformer(s). Simple slider stations for RGBA/W control would be preferable to keeping up with multiple battery powered remotes.

I wish I had more of the EDI fader stations. They seem really well built. I check eBay regularly, but equipment other than dimmer modules and full consoles rarely pops up.

Yeah, EDI made good stuff. I've got an original Scrimmer 2x6 chan console with the fluorescent tube illumination that I modified with RGB LED tape, a couple of CopyCat preset stations, and some 1x8 DMX splitters. A friend of mine was president of EDI for a couple of years. James at Northlight is great and of course can answer any questions on his products. I do wonder if his DMX to PWM board has enough current capacity to run a lot of LED tape, which consumes quite a bit of current. I think it's mainly used for driving solid state relays. Here is a link to a heavy duty unit that is DMX to PWM:
https://sirs-e.com/wp-content/uploads/2013/11/DMX-CON4-C2-UL-Datasheet-1.pdf
Cost might be prohibitive. I would find the specs on the LED tape you are considering and then go from there.

 

[DrewE]

It would be pretty simple to program a (basic) Arduino to act as a six channel potentiometer to PWM controller. You'd just need some sort of a switching device--a MOSFET of appropriate ratings would be a reasonable choice--for the output to control LED tape. It doesn't look to me like it would be too hard to hack apart the Lightronics control station and remove its microcontroller (and ADC or analog multiplexer chip) and connect the controls to something else. It's not a particularly complicated PCB, and the components and traces don't have fine pitches or excessively tiny clearances between them.

If you're rather more adventuresome, and depending on what microcontroller they used, it may very well be possible to throw together a program for it to output DMX512 directly rather than whatever proprietary protocol it's using without any hardware changes.

 

[Les]

@DrewE , you're speaking my language! I'm all for a bit of hacking - especially on the cheap. Come to think of it, there is probably some evidence of that in my post history, as @RonHebbard could attest. A lot of this is also just a way for me to learn electronics, while hopefully coming up with some useful gadgets (and knowledge) along the way. I really appreciate your input!