Your question needs clarification - You can shift a bit for any number of positions - 50, 100, up to 255 in a Micrologix standard file length, even more if you set up to shift across file boundaries.
However, being familar with what you are doing, now you want to shift 50 bits in parallel at one time. To do that, you have to use something other than a BSR or BSL. FIFO-type instructions (FFL and FFU for the MicroLogix)) will shift words (16-bits) at a time, so you would need 3 of them working together to shift 48 bits as a block. However, the mechanics will be difficult.
Other commands that will move 16-bits from one place to another are COP, MOV, and MVM. Using 3 or more instructions working in parallel will allow you to move any number of bits, if that is what you must do.
Why 50 bits? I thought you only needed 5 digital outputs for your project, which could be done with five BSR's triggered by some timed pulse. Of course in your case you are only needing to shift the bits ONE position, the bit distance-time between (sensing input and when output is needed). To shift a bit only one position seems kind of a trivial use of a Bit-shift register. A timer will do the same function with a lot less trouble. But maybe you are wanting to demonstrate advanced techniques with your student project.
If so, I can help with that. First you have to understand what a bit-shift register is and how it can be used. Like I said, you need to use an EVENT to trigger the shifting of the bits. If you use a pulse from the free-running clock (S:4) then your shift will not take place at the right time (PLC clock and your Rockband music are not synched together), so your output will never happen at the right time.
To make it happen at the right time, you must use your 5 Inputs as triggers for 5 BSRs (not S:4/0), one for each color. You shift the bits one position each time a new input happens. That way the game is controlling the timing. Your outputs will occur then at the correct time (the same time as it take for the next input, whatever it may be). If this makes sense to you, then there is some hope that you will get it working.
Also, in addition to using your Inputs to pulse the BSR, you must insert your Color Input into the BSR at the Bit Address. I see that you are inserting B3:5/0 into the Bit Address. I cannot tell what you have going into B3:5/0 (could be correct or not). Your BSR output is definitely not set up correctly, as you are using B3:0/0 to turn on your Green Output and B3:0/1 to turn on Strum. That means that Green will come on during the first PLC scan (when clock bit S:4/0 goes on), and will go on/off every tick of the PLC clock. I doubt that is what you want. Your music will be playing at an incrediably fast rate, and will have no relation at all to when your Inputs appear.
Attached is an example of a BSR instruction. The bits are shifted by Input I:1/6. Bits I:1/7 (Tall Bottle) and I:1/8 (Broke Bottle) are fed into locations B3:4/0 (Tall Bottle Register) and B3:6/0 (Broken Bottle Register). When the Broken Bottle bits shift 21 times and reach addresses B3:7/5 through B3:7/8 (21 encoder ticks later), we DO SOMETHING. Notice that the Encoder Input I:1/6 is controlled by the movement of a bottle conveyor belt. In your program, the time between your music note inputs IS NOT controlling the movement (shifting) of your bits. It is going to take a miracle for it to work like that.
