Helvar/ House Lighting systems and DMX

[Matt Riley]

Hi all,

 

My next challenge is to interface our Helvar houselighting system with our lighting desk. I believe the system is DALI compliant, and sadly isn't the version with DMX input <_< and so am looking at how to best interface DMX, or more ideally ART-net with DALI. The DALI standard is an ISO standard, so it is easy to get hold of, and I notice that a few manufacturers have made inexpensive DMX-Dali interfaces, such as these, these and these. I get the feeling that the DALI route, out of all of them is the best one to go down. I was just wondering:

• Do you think I'm barking up the right tree here?
  
• Has anyone done this sort of thing before?
  
• Does anyone have any recommendations for DMX-DALI interfaces?
  
• Does anyone know of any Artnet-DALI interfaces instead of DMX ones?
  
• Am I crazy to consider a little bit of DIY?
  

[dbuckley]

Based on past experience with their products, if the price isn't a showstopper, go with Artistic Licence.

[Tomo]

If they really are DALI, then unfortunately you probably won't be able to get them working in a way you'll be happy with.

DALI was designed to control office lighting, it's totally unsuitable for 'live' fades. (Read the XTBA DALI Watch manual...)

 

DALI has four basic modes of operation:

• Broadcast: Every luminaire on each 'loop' at the same level.
  ~60Hz max. update rate. (Good)
   
  
• Group: 16 Groups of Luminaires on each 'loop'.
  ~3Hz max. full update rate with 16 groups. (Poor). Fades are steppy and unsynchronsied.
   
  
• Individual: Individual control of each luminaire on each 'loop'.
  ~1Hz max. full update rate with 64 luminaires. (Awful.)
  Normal fades or snaps are "Hollywood Warehouse" style (without the sound effects!).
  To avoid that, the fade has to be very slow, somewhere around 60-100 sec minimum.
   
  
• Scene Mode: Recalls the 16 presets stored in the luminaires.
  Allows for good fades, but no direct level control is possible.
  This is probably the mode they are currently running in.
  

In Group and Individual modes, the update rates can be faster by having fewer groups/luminaires.

- For reference, DMX512 has a 30-44Hz full update rate.

 

All that means that DALI is not really suitable for theatrical houselights.

(Most likely they were chosen by the EC, and the consultant wasn't able to override them.)

 

DALI is great for worklight, cleaning lights, office, some foyers etc.

Just keep it out of the theatre!

 

Note:

- To use anything other than Broadcast mode the ballasts need to be addressed and configured.

- You cannot have two luminaires (actually ballasts, some luminaires are twin-ballast and count as two) with the same address.

- 64 ballasts on a loop is the absolute maximum.

- The dimming curve is nothing like any normal dimmer. 10% output is at 67% input!

 

That out of the way:

There are a lot of very fussy rules about DALI, and there are also several different types that can't always coexist.

 

None of the DMX>DALI convertors I know of can coexist on the same loop with any other controller.

You may find that it cannot be done without removing the Helvar controller completely.

 

DALI needs exactly one (1) PSU per 'loop'.

Some DALI controllers have a built-in DALI PSU, while some do not. It's important to check!

 

The various DMX>DALI convertors offer one or more of the above modes, some have a setting to select a mode.

 

I've used the AL DMX>DALI and XTBA units, both are good but they do have different feature sets.

[Matt Riley]

Hi Tomo - thanks for your reply. We're happy with the current quality of fades given by the hardwired helvar controller - I can't see any reason why this would go down using a DMX-dali interface?

 

The system uses Helvar Digidim 452 dimmers + a Digidim 910 router and a single Helvar 126 control panel at the moment for reference. I believe that the router allows multiple controllers (as it has 2 dali ports on it?)

[AHYoung]

dalis not quite the absolute disaster that's suggested, its a solid and robust way of controlling multiple fixtures in an easy to cable and configure manner. its not the defacto standard for wiring controllable lighting all around the world for nothing. Whats its not great at is real time control, but its not designed for live use and the low refresh rate means they the datacable is basically twin and earth mains. Its not true that the fades are steppy and uncoordinated, they just work a separate way. if you try and tell dali to fade by sending incremental commands, ie moving a fader, it wont work well, but what you do is send a command that says fade to this level over this time and send it to all the fixtures you want to fade and you get smooth fades. I cant see why you want more than the ability to select between a few preset levels and also fade to black / full on which is what your little control panel should do ,so sensibly you want a slave panel next to the desk as it will just work....

[Tomo]

dalis not quite the absolute disaster that's suggested, its a solid and robust way of controlling multiple fixtures in an easy to cable and configure manner.

I never said it was a disaster. Just that DALI is not appropriate for all situations.

 

Whats its not great at is real time control, but its not designed for live use

I agree entirely!

That's why it's rarely suitable for theatrical houselights.

 

That's because in theatre, every fade is a real-time fade with continuous updates. Theatre is live!

A fade might be stopped, slowed or reversed at any moment.

- A lot of the time, somebody really is sat there with a finger on a fader - and as you said, DALI is rarely appropriate for that.

 

That said, DALI Broadcast can easily run at a very high level update rate giving good, live-controlled fades.

(The curve's still really weird though.)

 

I cant see why you want more than the ability to select between a few preset levels

This is where you're mistaken.

Don't feel bad - it is a very common mistake.

 

In the majority of theatres, the lighting designer wants control over both the levels and the fade times.

DALI isn't designed for that.

 

I can't see any reason why this would go down using a DMX-dali interface?

The reason the fades may change is because of DALI's update rate.

 

Your current controller is sending the single command "All Play Preset X" or "All Off" when you press one of the buttons.

The luminaires then handle the fade themselves, using the fade time that's been stored in the ballast.

This method of control works really well for offices.

 

The Artistic Licence DMX>DALI interface can do the same as your existing 7 Scene & Off wallplate - but is that what you want?

 

Using the interface in DALI Broadcast mode will give you responsive control.

However:

• 
   
  
• All fixtures on the DALI 'loop' will be at the same level.
  
• You won't be able to use your existing wall plate and DMX>DALI interface at the same time.
  - When it's active, the DMX>DALI convertor will stomp on the wallplate commands around 30-40 times a second.
  

[dbuckley]

We're happy with the current quality of fades given by the hardwired helvar controller

 

So you like what you've got, but want different control.

 

Given you have a 910 router, I note in the brochure it says "OPC server software and Ethernet I/O commands enable interfacing to third party systems such as Building Management Systems".

 

Thus I would suggest this isn't a DALI interfacing problem looking for a DALI solution, but a TCP/IP interfacing problem looking for a software solution.

 

So when you ask

 

• Do you think I'm barking up the right tree here?
  

I think the answer is "no", wrong tree error.

 

The brochure strongly suggests that the 910 router has an OPC server in it. OPC is OLE for Process Control. (Wikipedia) - or it was, apparently its been remonikered to Open Platform Communications.

[AHYoung]

to clear up any confusion. my understanding that ive picked up working for 4 decades soley in the pro ents / arts industry ie its all ive ever done is quite simply this: .The lighting designer - a role ive performed oh so many times in the past is utterly concerned in the operation of the lighting instruments directed at the general performance area and wants precise instant and smooth realtime control. This is achieved using a lighting desk, dimmers and DMX controlled fixtures. Whats also required is a nice semi dark state around the auditorium before the fun starts and button that can be pressed to fade to black and another for a big bright go home state. The lighting designer wont care two hoots about any of this as long as the darks a dark and the darks on time.

 

I thik that Tomo is misunderstanding the simple purpose of houselights and seems to think that the LD would want to integrate them into the performance lighting, Indeed Dali would be inappropriate, but its highly moot as im yet to see a situation where the houselights became part of the show and on a per fixture basis ? , if that's a requirement, generally is a wash from an audience truss or the classic moles along the front truss whatever controlled from the same desk as the stage lighting. Horses for courses, Dali for your building, DMX for your Stage, no need to mix the 2...

 

The OP asked for a way of controlling the houselights from the board, the most appropriate way is to add a dali controller at the board and that will be the easy solution or if you have your dali lighting on your network, its also simple enough to use udp control if you want a homebrew interface or to integrate with an existing control system.

[J Pearce]

The fade time of the house lights is often used as a design feature. A slow fade reads very differently to a snap. It is also common to fade to half for overtures and then out for the top of the act, control of fade times and synchronisation with the main desk for a clean transition can be quite important.

 

In my opinion the show begins as the audience walk into the auditorium, if not before, not just at curtain up.

[dbuckley]

I thik that Tomo is misunderstanding the simple purpose of houselights and seems to think that the LD would want to integrate them into the performance lighting

 

I can't be the only person ever to integrate house lighting into cue states. The performance doesn't start when the houselights reach zero; the performance starts when the audience member comes in through the double doors, everything that audience member experiences after that is part of the show. I choose the level of the houselights as part of the mood setting, and to contrast with what will happen next.

 

And in at least one show (I'm thinking its a Farndale?) bad things happen to the electricity while the houselights are on; that requires the houselights taking part in the show.

[alistermorton]

I can't be the only person ever to integrate house lighting into cue states.

 

Exactly. The houselights are part of the overall lighting rig, and part of the mood setting of the show. They don't just preset fade on/off as the act begins and ends, and increasingly they may change colour, too.

 

 

 

[Tomo]

To the OP:

Can you clarify the goal?

 

1. Do you want to be able to 'virtually press a button' on your existing panel from the lighting console?
   
2. Do you want to control the level of the houselights from the console?
   
3. Do you want to control the level of the houselights from the console AND still press a button on the existing panel to override the console and turn the houselights on?
   

It may be possible to do #1.

This would be either using a "Preset/Scene-mode" DMX>DALI interface, or over Ethernet to the DigiDim 910.

- Quite a few modern consoles (eg ETC Eos and Congo families) have the ability to send UDP Ethernet commands as part of a cue, so you might be able to do that.

You'll need the technical manual for the DigiDim 910 though, and I have not been able to find one.

 

You can get #2 with a DMX>DALI, however the wallplate will not work when the DMX>DALI is active.

 

Your existing system simply cannot do #3.

You would certainly need to replace the wallplate, and probably the DALI dimmers as well.

Depending on the number of circuits, it may be better to get a theatrical DMX-controlled dimmerpack that supports 'backup stations' of some kind - eg ETC SmartPack w/ Smartlink, Zero 88 Chilli with ChilliNet etc.

 

The bits you have:

The DigiDim 452 is a 1-channel, 6A IGBT leading/trailing edge dimmer.

The DigiDim 126 is a 7-Scene + Off controller.

The DigiDim 910 is a two-loop DALI PSU and controller with internal timed events and some kind of Ethernet interface.

 

Unfortunately I have not been able to find anything that states the UDP commands for the DigiDim 910, only datasheet and adverts. You may need to contact Helvar directly for that!

[dbuckley]

If this PDF manual is to be believed, the 920 model of the router has DMX input capability, and that would probably be the fastest and easiest way to acheive what is needed.

[musht]

simple purpose of houselights and seems to think that the LD would want to integrate them into the performance lighting

 

Looked into replacing a DALI driven LED houselight system in a regional theatre a few months back, apart from being unable to reach 0% smoothly, thats an LED driver issue to be fair, the house was unhappy with the way the control functioned, unable to bring houselights up and down quickly during audience participation in lectures was one example they gave, unfortunately they didn`t have the 80K+ to rip out and replace the controls.

 

Houslights are a bigger subject than they would appear on the surface....

[Shez]

Indeed. At one of my venues (a very atmospheric Victorian theatre), houselights (all tungsten) are just on a manual pot. Over the last couple of events there, I've had them just glowing for cabaret, up & down to half for audience participation, slowly cheating in and out and various other fade times as dictated by the style of event. Full manual control is the only really workable solution there. Plus, I do love the gentle glow of very low tungsten :)