A synchronous high speed motion stop for a series of multi-top loaders residing on “n” controllers on one rail achieves effective detection of the servo-error status and shut off of the trailing controller's servo power within 3 ITP time. The control method reduces the unnecessary error recovery because it only shuts off its immediate trailing controller without aborting its leading controller, allowing the leading controller to complete the cycle tasks. The cascade control method produces a synchronous high-speed motion stop for the robots across the controllers and effectively prevents the collision between the robots.