Introduction

One of Camelot’s more unusual features is its ability to coordinate multiple copies of itself running on different computers. Why would you want to do that? There are numerous situations in which it could be useful.

Perhaps you prefer to have an iPad with lyrics in front of you onstage, while a laptop sits just out of sight running virtual instruments, playing hardware synthesizers, and providing a signal path with high-quality plugins for processing and effects. Or maybe you are in a show where you need to be able to instantly switch to a redundant system if there is a crash.

Basics

Camelot coordinates multiple copies of itself by designating one instance as the system master, and a second instance as the slave. The master, which, naturally, is referred to as “Camelot Master,” is assigned a MIDI output port and channel in the Settings view of the master machine. A connection is made from MIDI Out on the master’s MIDI interface to MIDI In on the slave’s MIDI interface. The MIDI In port is selected on the slave, the desired commands are configured, and off you go!

_{Figure 1 - The master (left) is setup to send commands over a specified channel and MIDI output port on the master MIDI interface. The slave (right) is set up to receive commands on a MIDI input port of the slave machine's MIDI interface.}

Recalling a Setlist, Scene, or Song on the master can cause a corresponding Setlist, Song, or Scene to be called on the slave. The connection is simple: calling Song 1 on the master will also call Song 1 on the slave. It doesn’t matter if they have the same name, all that matters is that the numbers match. This is a very flexible arrangement.

_{Figure 2 - A song called on the master will call the song with the same number on the slave, whether or not the name is the same.}

Scenes are always referenced by the Song they are in. If the master calls Song 2, Scene 2 and the slave only has one Scene programmed for Song 2, then nothing will happen when Scene 2 is called on the master.

_{Figure 3 - Uh oh. The master called a Scene that doesn't exist. Now what? Nuthin. At all. Nothing will happen on the slave; it will just ignore the command and stay where it was.}

Setting Up the Master

1.    Click the Settings button in the footer to access the Settings view.

_{Figure 4 - Oh, so many good things in the Settings view!}

2.    Click MIDI and then MIDI Outputs.

_{Figure 5 - In the MIDI Outputs panel, select the interface port that will be connected to the slave.}

3.    Choose the MIDI output port you will connect to the slave.

4.    Click Remote Control, then MIDI.

5.    Click To (another Camelot) to access the master settings.

_{Figure 6 - The To (another Camelot) panel is used only for enabling and setting up this copy of Camelot as a master that will control others.}

6.    Click the Enable switch to activate master control.

_{Figure 7 - After enabling this copy of Camelot as the master, a MIDI channel and output port are selected.}

7.    Click in the Channel field and enter the MIDI channel you want to use for control of a slave instance of Camelot, or use the plus (“+”) and minus (“-“) buttons to set the channel.

8.    Click on MIDI Port and select the MIDI port over which you want to send commands to the slave instance from the list shown. The list displays all ports defined in the Settings>MIDI>MIDI In panel, which can include USB ports and wireless MIDI. Also note the Camelot MIDI Output channels, which are virtual ports that provide interapplication MIDI connections to any other MIDI programs that may be running on the computer acting as the master.

Setting Up Slaves

1.    Click the Settings button in the footer to access the Settings view.

_{Figure 8 - Remember this guy? SO useful.}

2.    Click Remote Control, then MIDI.

3.    Click From/By to access the list of available MIDI sources.

_{Figure 9 - Once you click Remote Control>MIDI>From/By, you'll see a list of all of the available MIDI sources. Remote controls can be configured for each selected MIDI source.}

4.    Click the Camelot Master (read-only) entry on the list to select it.

5.    Click the “three dots” ( “…”) icon and choose Edit from the menu that drops down. The Camelot Master setup panel will appear.

_{Figure 10 - The Camelot Master setup panel allows choosing a MIDI input port to receive commands from the master, as well as the list of to which the slave can respond.}

6.    Click the Controller MIDI Port legend and choose from the list that appears the MIDI In port on the slave’s MIDI interface to which the master is connected.

_{Figure 11 - On the slave machine, the MIDI In port connected to the master machine must be selected for receiving commands.}

7.    Each of the commands in the list shown can be separately enabled or disabled. A receive channel can be set for each command, as well. That will be used in future versions, but, for now, leave all of the commands set to the default value of “ANY.”

_{Figure 12 - On the slave machine, each command can be independently enabled and set to its own channel.}

The commands available to the master fall into two categories: selecting and transport. The transport commands are simply the ability to play, pause, or stop the timeline. Selecting allows recalling Setlists, Songs, and/or Scenes.

You may not always want all commands enabled if, for example, you want Songs and Scenes on the slave to change, but don’t want its timeline to run.

Note that there will be some small amount of latency between the master and the slave in timeline operations. If your timeline programming requires precise timing, be sure to test and make sure that latency won’t be an issue.

Applications Examples

Let’s look at a couple of examples to give an idea of how the capability of running multiple instances of Camelot might be of use.

Remote Attachment Display

Camelot can run on an iPad as well as on a laptop. You can have a laptop doing all of the heavy lifting - running virtual instruments, controlling hardware synths, applying sophisticated effects and processing - and use an iPad only as a convenient display for lyrics, notes, and other attachments. In this scenario, the laptop might be the master and the iPad the slave, with a MIDI footswitch set up to change Songs or Scenes on the laptop. The connection between the two systems could even be wireless.

_{Figure 13 - A MIDI foot controller is connected to a laptop computer, which is the master. In this example, the master controls an iPad wirelessly.}

Attachments are made to Scenes, so the simplest approach would be to construct Songs and Scenes on the iPad with the same names and placed in the same order as on the laptop, with the Scenes on the iPad containing nothing but the attachments.

Conversely, if you prefer using the touch interface, you could make the iPad the master, in which case it both displays the attachments and calls up the corresponding Songs and Scenes on the laptop, or even a small desktop machine, which could be situated offstage. The iPad can also start and stop the timeline, which might have automated Scene changes on it.

Maintaining a Live Performance Backup System

Productions that use a lot of technology will often guard against technical problems interrupting the show by running redundant systems in parallel through the whole performance. Typically, the redundant systems will be identical to each other, but if that is not possible, the important part is that the two systems be able to function identically.

Camelot’s backup and restore functions can be used to make sure the backup system, which is set up as the Slave, has the exact same setup as the primary (Master) system. If you are unable to have a parallel system running in real time, Camelot can still quickly restore to any capable replacement computer.

In the event of a failure during a performance, the audio and MIDI signal paths both need to be switched over. Switching over the MIDI system could be as easy as moving a cable or two from the Master machine to the Slave. Moving audio cables in a live system can create glitches, and if a number of outputs are in use, it can take time. It is better to actually have identical audio outputs wired from each of the systems to a mixer, with the Slave outputs kept muted. If a failure occurs, switching over audio becomes merely a matter of muting the Master audio channels and unmuting the Slave channels.

_{Figure 14 - The master-slave connection can be used to run redundant systems. The master and slave are set up identically, and the master is calling the same Song or Scene on the slave that it is running. In the event of a computer crash or failure, all that needs to be done is move the MIDI In and Out cables from one interface to the other (dotted lines) and you're back online in seconds.}

Less is More

The commands available between master and slave are rudimentary at this time, but the strength of that is that simpler communications present fewer possibilities for problems, while the changes that can be effected by calling a new Scene on both master and slave can be huge.