DMX out (control DMX devices)

[ubijetz]

Am I correct in assuming that SCS 10.5 does not have the capability to control DMX devices (DMX out), only be controlled by DMX devices (DMX in)?
If so, do you have any plans to introduce this feature - I'd like to be able to run Intelligent light (multiple DMX channels), and simple lights, via DMX from SCS.

[Mike Daniell]

Yes, SCS currently just supports DMX In. It's feasible to add DMX to the Control Send facility, but there's quite a bit of work involved. Presumably in a DMX Control Send cue you would want to change the values of just a few selected channels (may be even just one channel). If you want to change the values of more than one channel and the channel numbers are not consecutive, then SCS would need to send separate packets for each channel or for each group of consecutive channels.

Then there's the matter of snapshot changes or variable changes, ie for any channel do you want to send just a new value (eg turning on or turning off a channel), or do you want to fade the channel from one setting to another setting over a specified time?

Finally, there are various overall control parameters that need to be set.

Could you give a bit more info on how you would want to use the feature, particularly regarding the number of channels you would want to change in one Control Send cue, and the type(s) of changes (which I have referred to above as 'snapshot' and 'variable' changes)?

[Theatre III Sound]

In my opinion, this is a function best left to lighting control desks and/or software. SCS already provides means of communication with lighting control systems via MIDI and RS232. As Mike pointed out in his reply, there are complications in adding DMX control which I'll expand on here.

In a given DMX universe there can be only one transmitter with the rest of the devices in the chain being receivers. If you wanted SCS to contribute values to a DMX packet, you would need to do one of the following:

1. Send packets from SCS via an interface (USB to DMX converter or Ethernet) to a DMX merger to be combined with a DMX packet from a lighting control system (usually on a "highest takes precedence" scheme). If a USB device such as the ENTTEC USB Pro were used, SCS would only need to send a packet when a value changes, otherwise SCS would need to produce a steady stream of around 40 packets per second.

2. Have SCS be the sole generator of DMX packets in the target universe or have SCS act as a merger by reading in a DMX packet from another source and then add its values and send the modified packet out to the universe. This would require SCS to receive and retransmit around 40 packets per second all the time.

And then there's the matter of timing as Mike pointed out. To control a dimmer for instance, you'd probably want to change the value over time (i.e. fade) while an intelligent fixture might require some values to change in discrete steps (i.e. snap) such as selecting a new gobo or moving the mirror.

All told, SCS would need to provide many of the functions of a lighting control system and I think that would overly complicate what is billed as a "sound" control system.

Bruce

[Mike Daniell]

Just to add a bit more to this, I agree with Bruce that this function is best left to lighting control desks and/or software. Many lighting software programs have sophisticated graphics to help visualize the effect of your lighting settings and variations, and this functionality will not be duplicated in SCS. I would only consider a very basic DMX Send feature, and then you must still consider Bruce's points about having only one DMX transmitter in a DMX universe, or using a DMX merger.

[ubijetz]

Thanks for your thoughts guys.
At the end of the day, I'm looking for one software controller to control both lights and sound, with theatre-oriented cue lists like SCS does.
In our scenario, we have conventional light dimmers that could be controlled by DMX, but we do also have Martin MX lights, which as you say are considerably more complex to control.
The problem with going the lighting control desk software way is that they tend to be oriented towards major light shows, as opposed to theatre usage, and the complexity ramps up beyond what we really need.
Do you think it would be feasible to talk in terms of SCS triggering the start and stop of action sequences that are all pre-programmed on a specialist lighting desk? Or are we then getting into the multiple sender scenario?

[Theatre III Sound]

Do you think it would be feasible to talk in terms of SCS triggering the start and stop of action sequences that are all pre-programmed on a specialist lighting desk? Or are we then getting into the multiple sender scenario?

Yes it's entirely feasible to have SCS send trigger messages to a lighting desk. A lot of desks support MIDI control which SCS does in spades. Search this forum and the general discussion one for MIDI to see some entries on MIDI control.

As to lighting software, have a look at LightFactory (http://www.lifact.com). This is a modestly priced package that can control conventional dimmers and intelligent instruments. You can create one or several lists of cues that can be triggered in sequence or individually via MIDI messages.

SCS and LightFactory (LF) can coexist happily on even a modest PC, although display real estate gets a bit tight. However, once LF has been initialized to accept MIDI triggers, it can run minimized, so SCS can occupy the whole display. I have done this using a 650Mhz Pentium III laptop w/320 MB of RAM using a virtual MIDI port package to connect SCS to LF with no problems.

If you'd like to not have all your eggs in one basket, you can run SCS on one PC and LF on another and communicate via real MIDI hardware (There's also some MIDI over Ethernet packages out there, but I found them to be a bit clunky to set up and operate). LF also supports control via telnet, but at the moment, SCS doesn't do that. Mike and I have had discussions about adding telnet to SCS, but there's probably not enough interest by the user community to justify it.

[preeves]

Hello Bruce,
Somehow I think we know each other from LF land, did not know you also resided here...

I have thought about this from another approach, and some months ago approched Mike (and Martin) about getting the SCS timecode into LF in the same way WinAmp does..Mike is waiting for me on this..

Although it does mean LF is the 'primary cue list' with LF controlling the SCS cue list via DMX, LF being able to listen to the SCS timecode completes the circle so to speak..

Any interest in that?

Mike I promise I am still working on things !!

Regards,
Paul

[Theatre III Sound]

Hi Paul,

Yes, I'm the same guy stirring up trouble here as well as LightFactory.

The only experience I've had with coordinating lights and sound has been a demonstration of this working with a production of "The Nutcracker" that I've worked on for the last several years. Last year, I ran sound using SCS for all the music. I've been showing the lighting person that SCS could trigger light cues as well as a good number of them are based on the music. So far the lighting person has been a little reluctant to give up the reins, so lights and sound remain as separate entities.

To make the demo, I just based the lighting cues on delays from the start or end of tracks. It takes a little finagling to get the trigger point for a light cue just right with the music because you have to take into account the response time of the lights (a small but significant issue).

I've never worked with timecodes, so I can't judge whether they'd be helpful or not. I know they are very precise. If LF and SCS were running on separate machines, how would the timecode be transmitted from SCS to LF?

While it's nice that Mike has provided the DMX in facility, I wonder how many folks are really going to use it because it requires additional hardware and cabling to get DMX into the machine that's running SCS. The same can be said about MIDI, although in the sound world it's probably more prevalent. But still, you need MIDI ports and cabling if you're going to run MIDI from PC to PC (or PC to Light Board). For those reasons, I'm thinking telnet (or some other network messaging scheme) may be the way to go for the case where you have two PC-based applications. LightFactory already can receive (and I believe transmit) messages via telnet and if SCS could do the same, then they'd make a great combination, IMHO.

(Aside to Paul: Want to get started on a common runtime interface for LF and SCS on top of all the utilities you're already working on?)