Hi, i would use some single scan conditional element, like a -|P|- contact before the shift block, or it will run on every scan.
If you would like to see what is happening with the bits, i would recommend using the memory field and setting it up like in this image. You can watch the bits shifting right. If the MSB is a 0, it will shift in a 0, and if it is a 1, it will shift in a 1.
I have attached an example as well.
v570 shift right example.vlp