Part B: Block Controller B
| Site: | QSC |
| Course: | Q-SYS QuickStarts |
| Book: | Part B: Block Controller B |
| Printed by: | Guest user |
| Date: | Tuesday, 3 December 2024, 9:19 AM |
Description
Video Transcript
0:08
Welcome back. Let’s dig a little deeper into the Block controller, and look at some of
0:12
the remaining types of blocks you have at your disposal.
0:15
Back inside the Block Controller edit screen, let’s look at another type of block. Look
0:19
under “Flow Control.” These blocks will only perform their action based on certain
0:25
parameters. It’s like a flow chart, where a decision point is made and a new path diverges
0:30
based on your answer. Let’s grab this one that says “if / do”. This block has a lot going on.
0:37
You’ll notice that it has a slot here at the top, which means it’s a command. It has
0:41
a slot here for a value or parameter, and it has an open mouth for what
0:46
we want it to do. It also has this cog icon, which we’ll talk about in just a bit. But for
0:52
now let’s integrate it with the rest of our program.
0:55
In the previous video we made a button that changes its label or Legend to “ON”
0:59
when it’s pressed. But in order to change that label to “OFF” when the button is
1:03
pressed again, we’re going to need the program to make an evaluation. If the state
1:08
of the button is ON, then we want the label to say on. If the state of the button is off,
1:14
then we want the label to say OFF. That’s flow control. So let’s undock our “set control”
1:20
block from the “control change” block, and add it to our “If” block instead. Now we can
1:27
drag the “If” block into the “control change block.” Essentially, when the button
1:31
is pressed, it’s only going to change the label if a certain requirement is met.
1:37
You can guess which part we need to complete now – if … what? We’ll need to add a
1:43
block here that equates to “if the control is on.” Next let’s look under the Operators
1:50
branch. Operators are things that, well, perform an operation. In this case, usually
1:56
mathematical operations such as basic arithmetic, or logical operations such as comparing
2:02
the equality of two different things. That’s what this Logic block does, that says
2:06
“blank equals blank.” This will work perfectly for us, so let’s snap this to our “If” block.
2:13
Now we see a new type of block connection. Rather than slots on the edge, this
2:18
block has holes. We’ve seen the type of block that fits in this hole before, with a triangular
2:24
tab on the side, right? These are values, or parameters. If we go back to our
2:29
“AMAZING” control branch, let’s grab this parameter: “AMAZING Boolean.” If you’re
2:34
not familiar with the word Boolean, it basically means a binary state, something that
2:38
only has two options, like our button. For our second hole, let’s look back in the Values
2:44
branch, and we’ll grab that “True/False” block. We can snap this into our Logic block’s second hole.
2:51
So let’s read our program so far – when the control changes, if the control’s state is
2:57
true, then we’ll change the label to “ON.” All that’s left is to define what happens
3:02
when the state is false. But where are we supposed to define this? There are no
3:06
more empty slots in this block! To fix this, we’ll have to use that cog icon we saw earlier.
3:12
Certain blocks like this one can have customizable configurations. This little window
3:17
that pops up is sort of a miniature version of the Block controller interface. On
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the right is our block, and on the left is the library of possible things we can add to
3:27
that block – just like the main interface. Let’s drag a new option into our block – the
3:32
“Else” option. When we add the “Else” in this configuration window, we can see that
3:37
the block itself has changed in the main window. We now have a new area to add a second command.
3:43
Let’s close the configuration window by clicking the cog icon again. We need another
3:48
“set Legend” block for this new section, but we can simply copy and paste our first
3:52
one. Most Windows shortcut keys work in the Block Controller editor. I will Control+C
3:58
to copy and Control+V to paste, and add this as our “Else” command. All that’s
4:03
left is for me to change the Legend string from ON to OFF.
4:08
So let’s read our script one final time. When the control changes, if the control’s
4:13
state is true, we’ll change the label to “ON.” Otherwise, we’ll change the label to
4:18
“OFF.” Looks good! There are a few final things I want to show you before we’re
4:22
done. First, we have to press this yellow “Save changes” bar at the top in order for
4:27
this code to become active. This allows you to work on your program on a live system
4:32
without disrupting anything. Until you press “Save Changes” the old code is still running.
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Once I press this, we can return to the Designer schematic to look at our button, and
4:42
make sure it works. When I turn the button off, the label says OFF. When I turn it on,
4:47
the label says ON. Excellent!
4:51
Okay, you’re right. It took us ten minutes to get a button to change labels, it’s not
4:55
that impressive. YET. We just did this as a tutorial on how the blocks connect to each
5:00
other. In reality, you’re going to do far more complicated things with the Block controller.
5:05
For instance – one important thing you should know is that you can stack commands
5:08
on top of each other. These blocks may look rigid, but they’ll adapt their size to whatever you need.
5:14
Let’s say I wanted to change the color of this button as well. I could add a “Set Color”
5:19
command into this block, and the block will adjust to accommodate it. You can add
5:24
as many commands as you want this way – which means that when the button is
5:27
pressed it can change its label and change its color, and reset another control, and
5:33
start a timer, and activate a third-party lighting device, and change the layer that’s
5:38
visible on the UCI, and launch the pyrotechnics, etc., all at the same time. Now we’ve
5:44
got a button that’s doing a lot more than changing its label. That’s the point. That’s
5:52
where we’re headed. But for now, I’m going to keep mine simple, and add commands
5:57
that simply make the button green when the button is on, and red when the button is off.
6:04
Once again I can save my changes, and then back in the Schematic I’ve
6:09
got a button that changes its color and its label as you interact with it.
6:14
Another very important thing in the Block Controller – if you right click on a block,
6:19
there are a couple of options for you. You could select “Show Comment” which gives
6:23
you a comment section at the top of the block. This lets you type in whatever you
6:27
like, which has absolutely no effect on the functionality of the block. So if you want
6:32
to remind yourself what this block does, you can give it a title. You could also choose
6:38
“Collapse Block” which will truncate the block down to a single visual line, without
6:43
changing the code. This can be very convenient if you have a lot of blocks in your
6:47
program and need to focus on one at a time. The jagged scale line indicates that
6:53
there is more to see, and you can always Expand the block again to reconfigure it.
6:58
Alright, one final thing. I saved the best for last! We mentioned earlier that the Block
7:02
controller is a great bridge between people who don’t write code – like me – and the
7:07
ability to accomplish things that require scripting. Well these visual blocks are literally
7:12
writing the code for you, and you can read that code by navigating to the “Lua” tab.
7:18
This is the Lua script of what we’ve done so far. This stuff at the top is just housekeeping,
7:23
while the block we built is represented down here. You can even kind of read it,
7:29
now that you understand how the language is structured. If you knew how to
7:32
write script before this, you could have written all this out rather than use the Block
7:36
Controller at all. But if you typed anything wrong, if you missed a capital letter, or if
7:42
you weren’t exactly sure how to format it, then the script wouldn’t work. The Block
7:46
Controller takes all that worry away by letting you build your program with easy to
7:50
manage puzzle pieces, and the code is written in the background – free of any syntax errors.
7:57
If you’re interested in learning scripting, reading this Lua tab might help you on your
8:00
way. In fact, if you want to further edit this script yourself now, you could select this
8:06
icon at the top and choose “Convert to Script.” However, a warning will pop up now,
8:12
and with good reason. You can convert blocks to script, which allows you to continue
8:18
editing in Lua, but you cannot convert those edits back into blocks. Once you select
8:24
OK, the interface changes to an editable text scripting screen. You do have the option
8:30
to “Revert to Blocks” but doing so will revert it back to its original blocks, so you
8:36
would lose any changes you made in Lua.
8:39
So, that’s the Block Controller component. We obviously only skimmed the surface
8:44
of what it can do, and what each of the different blocks in each category are. Mostly
8:49
we wanted to show you how the blocks connect to each other, demonstrate how
8:53
some are customizable, and hope you feel comfortable navigating the edit window
8:57
now that you know what options are available to you. In upcoming videos, we’ll go a
9:02
little slower and talk about the concepts of a programming language, and see how
9:06
each idea is implemented both in Lua and in the Block Controller. Thanks for watching.
Lesson Description
Learn about sections of the Block Controller, including control change, flow control, if statements, operators, boolean values, and converting blocks to lua script.