Disclaimer: I'm a PC techie, not a lighting techie, although I do have some understanding of the latter.

I notice that some companies are advertising USB -> DMX512 adapters. Bearing this in mind, it would be possible for a PC application to control DMX-based equipment, either for specific specialist applications or for general purpose applications such as lighting desks.

My question is, is this done in practice? I can see that most people would be happier with real live knobs to twiddle, but in principle you could control DMX kit from a general purpose "Mixer-type" application running on a PC.

I'm always interested to hear if people have experience of this.

It can be done, but what do you do when the pc crashes with the audience all waiting with baited breath!

The flippant answer of course is to say "stop playing solitaire at the same time, and reboot".

This is a fair point (and where real-time software is concerned, a very important one). Is it based on any personal experiences of lighting rigs, or just PCs in general?

You can get the same problem with a computerised lighting desk locking mid show although its less likely.

If you were going to use a PC the only thing you would have on it would be the show software and that would be all it could do so you shouldn't have a problem.

The LanBox seems to be the item of choice although maplin do a cheaper variant with software etc.

h

To be fair, they can work quite well. PC reliability and reboot time is an issue, particularly with Windows but also with Linux etc. Some desks are built on PC technology, as are many firewalls etc, but they all use a cut-down kernel and its generally on-board using an EPROM or similar device.

If you want to do it on a Windows based PC, you can make things a lot more stable by tuning XP for real-time applications. Load the PC with as much memory as it will physically take, and make sure you have a fast boot disk formatted NTFS. Make certain you have the latest version of all drivers especially the video drivers. Take all junk programs off the machine, defrag the disk regularly and fix your pagefile size. By cutting out prefetch etc you should be able to get boot time to under 30 seconds on a reasonable speed machine.

Set your power settings to 'Never' powersave, hibernate etc. etc. You do not want this machine shutting down the disk because there has been no action for 20 mins.

Then download free Smartclose and run it before starting the show software. This will kill off all applications, services etc that you do not need and disable the screensaver.

You are now ready to run with a machine that will fly, be incredibly reliable and if it does fail should have you up and running in under a minute. However, that can be an very long time when you are waiting for a cue!

DO NOT THEN LET YOUR KIDS NEAR IT unless you want to go through the same headache every show! They will load all sorts of codec's etc that may cause the show program real problems.

Robin

PCs in general, video editing systms in particular. Lighting would not be such a problem as someones show falling off the air is not as critical to the world in general as the Ten O clock News disappearing!
Obviosly it is critical to those taking part! The way I see things going is the idea that a DSM rather than calling a cue will press a button. Efficiencies there! Though sadly from their position off stage left they did not see that the set had collapsed stage right and there should be a pause!

The lanbox is the only real alternative and at 550 Euros (plus your laptop) not bad value - you can link upto 8 together on a router to give 8 universes.

I've put my views accross as an owner on other threads but simply put - it's okay - using your PC to programe is okay and it does some stuff very well. Personally I despise the cue stack and if you need to sort something out mid show - forget it.

That said it has a very clever way of controling scrollers, but doesn't have some more advance tricks.

My current desk of choice it the ETC Congo junior with a playback wing of 40 faders - can be used as a standard theatre desk or busk live. having played with it a lot - its fab - there is NOTHING you can't do quickly - in fact this desk has remove some of the skill of programming because it's so easy. I wish I had it whaen I was doing a lot of pro programming,

The bad news it that it retails for ?6K BUT a frog 2 is ?8K and it's miles better than the strand 500/300 ever was (plus you get 3000/1000 channels as standard) - Currently this and it's big brother are going into 90% of theatres and larger schools although Grand MA is starting to be popular (if you have ?30K to waste - I'm not a fan)

eeeeek I'm just plucking up enough courage to DSM again! Just about coped as it was. Seriously though, it does seem a bit silly to have all the possible pitfalls of someone calling and someone pressing. The degree of vision, even with monitors can be a problem, especially if like last year the crew weren't good about using the cans and liaising to see the stage was clear, thus we had tables appearing in street scenes, for instance. I'm bringing in my own crew this year.

Martin, I dont know where you would buy a Frog from but they are ripping you off at that price.!Top of the range no discount maybe ?5k.
Hang on you work in the supply trade now!

Frog 2 list = ?7k.

Robin

THis is all very interesting. I saw a usb->dmx adapter at http://www.usbdmx.com/usb_dmx_interface.html, and wondered if the panel thinks it has any potential. It looks low cost but is hardware only.

Whats "list"

Not at all familiar with the new Frog range but I assume there is the breadth of the old range, so I am surprised that the only one lists at ?7k!

That's the Frog 2, Nick; it's been available for some time and is a bit of a different beast to the 'basic' Frog range - four universes, two monitor ports, support for touchscreens, CD writer, ethernet and all that jazz.

As I understand it, the new Frog range (whatever they're going to be called) are going to be pitched around the same level as the original Frogs, although what they're going to be called is something I've been wondering about. Frog 1.5? I guess we'll see next month when they're launched.

As for PC control - nah. Give me a physical control surface any day. I guess it might be alright to run the show if everything went to plan, but the moment you have to fill in for something that's tripped or blown, or the talent decide they're going to stand on a bit of the stage that you hadn't planned on them being on when you programmed the scene, and I think I'd fall out with the computer very quickly.

I could be convinced to try doing a show from a PC with a wing attached, but the idea of having to change things on the fly with a mouse doesn't really do it for me.

Its not just me that's had that experience then?

Its one of the fundamental rules of being an actor I think...... Attracted by the lights, but then stand just outside the beam.

Your'e right Nick - what is list... (but I'd scare you if you saw my buy prices

Thanks Robbin for your correction - I knew the figure was somewhere out there and couldn't be bothered to look at the price list....

Desks are horses for courses, The congo junior I mentioned above is actually ?5.8K with palyback wind or?3k without - given how much better it is than frog - I think the extra money is worth it (unless of course you don't have the extra money

Thanks to all for their thought so far.

I think can summarise the answers to my question as: Using a PC as a mixing desk is possible, given appropriate an DMX interface and suitable software. The main drawbacks would seem to be software reliability (and I work in IT so I see exactly what you mean by that!) and the relative ease of use of "real" buttons and sliders as opposed to mice.

Does that seem like a good summary?

Does it for me !

I guess that running the show from a PC is a personal choice. I wouldn't feel comfortable doing it, but I haven't heard of any horror stories about PCs crashing mid-show. I have heard of many shows running with a PC as backup, but this is slightly different.

Dave

As a side issue;-

This new Rosco product may be of interest, that allows audio cues to be operated from your lighting control board;-

http://www.plsn.com/index.php?option=com_c...d=1611&Itemid=1

This is partly related to the original question, honest, but does the panel recommend an entry-level mixer control board for light amdram use. I know that the answer is that "it depends", because I haven't specified the number of channels etc., but is there a typical "starter" product that gets used a lot?

To get you started I would suggest either:

1) a Sirrius 48/96 from e-bay. This desk is now 20 (I guess) years old and loads of people have learnt on it. It is a good work horse for generic lighting once you get your head around the fade timers. This is a very basic desk.

http://cgi.ebay.co.uk/ZERO-88-SIRIUS-24-LI...VQQcmdZViewItem

2) the range of frog desks appear all over the place at the moment

http://www.zero88.com/en/products/2

3) the Jands Event series is also popular and is largely equivalent to the Frogs

http://www.jands.com.au/jandsweb/lighting_con.html

hope this helps

Dave

Don't forget ETC Smart Fade or ADB Tango or even Zero 88 Jester

Re Dmx interfaces - a friend of mine built on - and it didn't work - even after putting it on an ossilascope to ensure the strat timing codes etc were right - it didn't

The main issue (IMHO) with cheap dmx interfaces, apart from the fact you use a PC to control is the lack of the little things - sure they can fade up or down a set of channels - but groups and pallets are mostly beyond them. The lanbox does most (I now carry it aroung to demo moving fixtures as it fits in my laptop bag) but it is oh so painful!

The hog wing and Jands Vista T2 go some way to over come this - you get a dumb wing with all your touchy feely controls with your PC having the software and processor. It must be said they are a lot easier to drag from place to place on the train and in the car rather than a full size desk and monitors..

I currently have the most evpensive fightcase for my full size congo (only a loan item unfortunatly) it's call an Audi TT - I can confirm that the congo and 3 19" monitors etc fit snugly with enough room for me to caryy a passenger to help my lift it out at the other end!

That reminds me, I must service my 48 way Sirius and sell it!

I personally use computer based software on a regular basis, and get along with it quite well!

As for software lag and failure - if you are using a half-decent computer, then this really wont occur. my computer can hack running lighting software and teccan at the same time, so i dont see how a computer dedicated to lighting only can have any more chance of crashing than any strand, etc or any other desk!

Using multiple monitors is a good idea, though - laptops usually have a spare VGA port on them, and it doesnt hurt to get a spare LCD going for a channel display - it gets slightly un-nerving when all you can see is a cue list in front of you!

the only real quabble i have with using software rather than a desk is that there are no faders to resort to in times of err... trouble - you can get hold of USB sliders for about 400 Squid if you really want to push the boat out, though, havent bothered personally though.

I've seen shows run using software really well, and also really badly - if youre going to purchase the kit, then make sure you've got several hours to play with it before running a show! its quite a bit different from any conventional desk, and Movers / Scrollers can sometimes prove a challenge!

I know a lot of lighting techies whinge and moan about people using software rather than a desk, but when the day arrives that you can play Solitare on a Strand 530 as well as Run a show, then ill start to listen

The reason I started this thread, apart from a general interest in such matters, was that I spotted some USB->DMX adaptor hardware and wondered if there was any market for a new lighting controller application for the PC. My professional background is as a developer of software for the PC, and I was wondering if there was any money to be made here, providing a "better mousetrap". I suspect that there isn't a lot of money out there for this kind of thing, but if anyone thinks differently maybe they can get in touch with me. Software, like performances, takes a lot of time to get right!