So, the way to use the PC Scroll Midi Type has been getting some people confused, and this blog post is meant to put and end to that! It is really simple, I promise!
What it does
This PC Scroll allows you to send incremental or decremental PC messages. That means that when you tap the switch programmed with a PC Scroll Up, and if you are sending out a PC#5 message, the next tap will send out a PC#6 message. If you are using a PC Scroll Down message, the next tap will send out a PC#4 message.
Parameters
Each message will send out a PC message. Depending on the value 2 parameters, Number1 and Value 1, the PC# to be sent out will be different.
N1: Valid between values 0-7. Selects which number, out of a set of 8 numbers, to scroll.
V1: Determines if the the number selected should be increased or decreased or remain the same. Using a value of 1 will increase/decrease the number, while value of 0 will not change the number.
How it works
The PC Scroll type select from an array (or container) of 8 numbers to scroll through. Let us assume that the values in the array are currently like this: {0,0,0,0,0,0,0,0}. That is eight 0s in the array. You can select any of the 8 numbers to scroll by using a range between 0 - 7 for the parameter N1.
If you select a PC Scroll Up message with N1 = 0 and V1 = 1, pressing the switch once will cause the array to look like this {1,0,0,0,0,0,0,0} and then send out a PC#1 message. You will simply be scrolling the first number in the array, since N1=0 selects the first number in the array. Stepping on the switch again will send out a PC#2 message, and your array will now look like this: {2,0,0,0,0,0,0,0}. Now, if you have another switch that is programming as a PC Scroll Up, with N1 = 1 (selects the second number) and V1 = 1, pressing that switch once will send out a PC#1 number, and cause the array to look like this: {2,1,0,0,0,0,0,0}.
Scrolling Multiple Devices Together
If you would like to scroll two devices together with one switch, you simply have to send 2 PC Scroll messages to the respective device channels. Your first PC scroll message will have N1 set to select the number you want to scroll in the array, while V2 will be set to 1, which will increase or decrease the number depending on the scroll type you chose.
For your second PC Scroll message, you have two options.
If you want it to receive the same PC number as your first device, you need to set N1 to be the same as your first message. This will select the same number in the array as your first message. If this is what you want, you will also need to set V1 = 0, so as to not increase/decrease the number. This is because the number has already been changed in the first message, with V1 set to 1. If you set V1 = 1 in your second message, you will notice that your PC number will increase/decrease twice.
If you want to scroll the second devices using a separate switch and number, simply set N1 to a different number from the first. For example, if the array is now {2,0,0,0,0,0,0,0}, setting N1 = 1 and V1 = 1 will allow you to scroll the second number from the array. Hence, if you are using a PC Scroll Up message, pressing the switch once will send out a PC#1 message, and the array will now look like this: {2,1,0,0,0,0,0,0}.
Final Thoughts
The PC Scroll Midi type gives you a lot of flexibility in determining how to scroll your device(s). If there is any other way you are using it, please feel free to share!