Lesson Description
Advanced Control Tree
7m 27s
Explore more of each control's metadata properties available in its Control Tree.
Video Transcript
Advanced Control Tree
7m 27s
0:08
Now that we’ve added controls into our scripting environment, let’s look at some more of each
0:13
control’s metadata available through its Control Tree. By now you should be very familiar with
0:18
.Value, .String, and .Position for most controls, so next let’s look at some more of these properties. In
0:25
upcoming videos we’ll explore how we can create functions to actually change each property, but for
0:31
now let’s just make sure we know what properties are at our disposal.
0:35
First, there are some visual options. .Color, for instance, changes the main visual color of the control.
0:42
You might find it useful to change a fader’s color when it approaches the limits of its range, for
0:47
instance, or when its channel is muted.
0:51
The .Color property can be represented by hex color codes, as well as all web-safe HTML color names.
1:00
In the Block Controller, you can set this with the “Set Control Visual” block. If you don’t like any of
1:07
these 70 colors, you could use a different selection option here in the Values category.
1:14
And if we look at the Lua generated by this Block Controller, we can see that we’re simply assigning a
1:20
value to the .Color control tree.
1:24
The .Legend property refers to the control’s label. This is different than the name you provided when
1:31
you created the control, Kevin, which cannot be changed by the script.
1:35
The Legend is the same thing as typing on a control to rename it, but since you can change the
1:41
Legend dynamically with scripting, this is a great way to change a button’s label based on its status.
1:48
In the Block Controller, you’ll find this represented by another “Set Control Visual” block. These “Set
1:55
Control Visual” blocks are all the same block with a different visual preselected, so I could simply
2:01
change this drop-down here to change its target.
2:05
While we’re here, let’s actually look at these other ones. .IsInvisible is a property that can be
2:11
set to either “true” or “false” to make a control invisible or visible again. You might use this,
2:17
for instance, to hide certain telephone controls on a UCI when the telephone is in use.
2:23
Similarly, the .IsDisabled visual choice will make a control semi-transparent and non-interactive. This
2:31
lets the user know they can’t currently engage that control in its current state.
2:36
The .IsIndeterminate property is another example of a disabled button, although you’re less likely to
2:42
force this state upon a control as you are to read this property from a control.
2:49
When a peripheral device is not connected to the network, for instance, its controls take on this
2:54
faded red color, which is the result of being Indeterminate. It means the system cannot determine
3:00
the connection between the control and its parent device, and thus it Is Indeterminate.
3:07
Let’s say you’re monitoring a fire alarm contact closure on an IO frame – you could monitor both the
3:12
control’s Value for any sign of a fire alarm, as well as the .IsIndeterminate property. Because if this
3:20
property becomes true, then you know you no longer have a connection to that device, which means
3:25
your fire alarm system won’t work.
3:28
You might notice that a Knob has its .Value, .String, and .Position properties available here in the
3:35
Block Controller, but a Toggle Button has something different – it has a property called .Boolean. For
3:42
a control that only has two states like a binary button, .Boolean essentially represents its Value.
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When referenced on its own, .Boolean is assumed to be true, but you could change .Boolean to false
3:56
to deactivate the control. In Lua script, however, you can reference a button’s .Boolean property as
4:02
well as its .Value property, or .String, and.Position.
4:07
For input controls, there’s a very important control tree property you’ll see a lot in upcoming videos:
4:14
.EventHandler.
4:16
In a world full of events, someone has to handle them! "Consider it… handled."
4:25
A Control’s EventHandler is triggered whenever the control’s state is changed. Basically it’s the
4:31
indicator that something has occurred, which you could use to initiate an action. This only makes
4:38
sense as an incoming control tree - and we’ll use it a lot when we start writing functions.
4:43
If you want something to occur when the button is pressed, you’ll use the .EventHandler to make
4:48
that happen. In the Block Controller, this is represented by this “on control change” block, which – if
4:57
we look at the Lua generated - is the beginning of a function, initiated by our good friend the
5:02
.EventHandler.
5:04
Certain types of controls have the .Values property – that’s plural Values, which is different than
5:11
.Value. For instance, a Meter could deliver both a peak and average value as an array using this.
5:18
There’s also a .Choices property for controls with drop-down selection menus.
5:25
For Output Controls, you might use the .RampTime property to set a length of time for a control to
5:32
change from one value to another, so the next time you set that control’s .Value or .Position it will
5:39
take this amount of time to arrive there. The .RampTime property is expressed in seconds.
5:47
Finally, let’s look at Trigger buttons. We’ve said a few times that Triggers are unique because they
5:53
don’t have Values, Strings or Positions. Normally you could change a control’s state by adjusting
5:59
those properties, but for a Trigger you’ll need to do this: Control:Trigger().
6:08
Notice the use of a colon instead of a period here. The colon indicates a method, rather than a
6:14
property. A method is an action that a control can perform. You don’t have to set the :Trigger to true
6:23
or false, the colon is all you need to activate this method.
6:28
There are a number of Control Tree methods you’ll find for certain controls. You’ll see them when
6:34
you start dealing with Timers which have a :Start and :Stop method, or TCP Connections that have
6:41
methods such as :Connect, :Disconnect, etc.
6:45
We won’t get into the creation of Lua TCP connections in this online control training, because it’s
6:51
much easier to use the Block Controller to send and receive strings across the network. And if you
6:57
want to activate a Trigger in block controller, you’ll find a specific block for that control
7:02
which activates its method.
7:05
Alright, we’ve gone as far as we need to in the Control Tree for now, so let’s go back to the Control
7:09
Worksheet. There’s no real exercise for this one, just a demonstration of some of these properties.
7:14
Take a look, and then we’ll finally get to move forward with creating some functions, so that your
7:20
script can actually do something! Move on whenever you’re ready.
Downloads and Links
Advanced Control Tree
7m 27s