Bit Shifting

Getting closer to understanding BSR/BSL but I still cannot understand the "CONTROL" address function. I am using R6:10 and I can see the 0's amd 1's do their thing, but what purpose is the control segment of this instruction? Also I gave the BSR a length of 8 but bits shift all the way to 15 on a BSL instruction.

Going to go shift some bits at home and will see what the control has to say about that.

The 'Control' (R registers in AB PLC's are just data blocks that the PLC uses internally to keep track of what the instruction is doing.

If you have played much with AB SLC/PLC processors, you might know that on older CPU's, you needed to reserve a block of integer registers for things like a PID instruction. Newer series CPU's introduced the "PD:" data file. They both store the state and control information so the PID equations could function, but the PD: type is much more user (and, I assume, even processor) friendly.

Open the data table address for R6:10 and compare what you see there with what's in the box in the ladder rung for that instruction.