What do SHIFT instructions do?

• A. They permanently offset COMMAND POSITION steps and motion to position variables by a fixed value.
• B. They reset all position variables to zero.
• C. They adjust the robot's speed by a shift amount.
• D. They temporarily offset COMMAND POSITION steps and motion to position variables by a value in a referenced position variable; SFTON and SFTOF.

Answer: (D)

SHIFT instructions create a temporary offset to the commanded positions by the amount stored in a referenced position variable. When the offset is activated, all following COMMAND POSITION steps and motion-to-position commands are interpreted with that extra amount, so the robot moves as if the target has shifted. The offset remains active only while SHIFT is on; turning it off returns to the original, unshifted targets. This changes how positions are interpreted rather than permanently changing stored positions, and it does not affect speed or motion parameters. The key idea is that the offset value comes from a position variable, allowing dynamic adjustments without editing the movement program.