OK. Here's a more indepth response with images. It's a draft that gonna be published on the Hub (so I'll remove it from here once that article is published) on how to control a Cable Switcher in Logic's Environment. Although this is based on using any connected MIDI Controller, the same same concept should apply to MIDI Touch on your iPad...
How to Map a MIDI Controller to a Fader in Logic's Environment
In this example, I want to map a rotary fader on my MIDI Controller to remote-control a cable switcher in the Environment. This cable switcher switches between different arpeggiators. If you want more info on how to create a multi-arpeggiator Environment check out these MPV Hub Tutorials (free) here:
http://www.macprovideo.com/hub/logic-pro/creating-arpeggiated-patterns-logic-pro-part-1 and
http://www.macprovideo.com/hub/logic-pro/creating-complex-arpeggiated-patterns-logic-part-2
Step 1
Open the Environment window (Window > Environment) and navigate to your Clicks & Ports layer from the Layer menu in the top left above the Inspector.
You can see that the Physical Input's Sum port (basically the input from all external MIDI devices connected to your Mac and recognized by Logic) is connected directly to the Cable Switcher. This in turn is routed Sequencer Input (Logic) directly and via a number of Apreggiators.
The MIDI signal from the Physical Input will travel from your MIDI Controller to the Sum to the Cable Switcher where you can choose which cable (or route) it will take before reaching the Sequencer Input.
Step 2
Create a new Monitor Object (local menu: New > Monitor). We're going to use the Monitor object to see what MIDI messages are being sent from the MIDI Controller. Click and hold on the Physical Object's Sum cable output and drag the cable to the Monitor.
Now, move the rotary knob or fader on your MIDI controller. You should see MIDI messages appearing in the Monitor object.
In my case, the rotary knob is outputting CC data on Channel 1, Data Byte 1 = 7 and Data Byte 2 (value) depends on the position of the rotary knob.
Step 3
Now that we know the rotary faders MIDI value we could simply select the Cable switcher and match its input value to the CC - 1 - 7. However, while this will work great with regular environment faders and objects with a range of 0-127, in this case the Cable switcher has 6 outputs - not 128 - so its range is 0-5. We need to find a way to map the range from the rotary fader to our
Create a new Transformer object (local menu: New > Transformer). Connect the Monitor to the Transformer and the Transformer to the Cable Switcher as shown below:
And before we move on to the next step, click on the Cable Switchers name to select it. In the Inspector you'll see the Input values for the Cable Switcher.
In my case they are:
- CC (Control)
- Channel 1
- DB 1 = 20
- Range = 0-5
Step 4
So, we need to transform CC 17 to CC 20. Double-click on the Transformer object and set up the Conditions and Operations as shown in the image below. (Click on the image to see a larger version).
Make sure you've got the Mode set to Apply Operations and let non-matching events pas thru. If you filter out other events it will prevent your MIDI notes passing through this object into Logic!
I'd also recommend not to use CC values such as 7 (volume) and 10 (pan) as the Cable Switchers Input as this will potentially mess with the selected track's channel strip!
Step 5
If you've tested how this works with a rotary knob you'll notice that you'll speed through the first 6 settings (value 0-6) and be stuck on the 6th output from your cable switcher from value 7 until 127. This is far form ideal!
We're going to use the Transformer's map function to assign more than each value, between 0-5 in the cable switcher to more than one value on the rotary knob of your controller. For example, I divided 128 (total number of values outputted from my rotary fader by 6 (total number of states/values of the cable switcher). From that figure I estimated that I'd like:
- 0-21 to be mapped to Cable switchers 0 value
- 22-42 to be mapped to Cable switchers 1 value
- 43-63 to be mapped to Cable switchers 2 value... etc.
OK. Here's how to set it up. In the Transformer make sure the Operations area for the Data Byte 2 column is set to Use Map.
In the Map area each vertical bar represent one MIDI value between 0-127. By default 0 is mapped to 0, 1 mapped to 1, 2 is mapped to 2, etc. We can change the mapping and set the first 22 to 0.
I'd recommend dragging with your mouse over the map display to set everything to 0.
In the first text field (bottom left) choose 1 and set its corresponding mapped value to 0. I repeated this process until left value of 21.
Now repeat this process as needed. If you have a very steady hand you can drag to create values on the horizontal plane - or at least get an estimated value. It will take a while to do this, so once done make sure to save your project!
Conclusion
Once you've mapped the values appropriately you can close the Transformer window and test out how the knob on your MIDI controller works when controlling your Cable switcher.
Bear in mind that if you want to use buttons on your MIDI Controller to switch between different outputs of the cable switcher there's no need to use the Map and its much easier to set up!
Hope this helps!
