An interlock system acts in conjunction with an arrangement in which selected ones of first and second pluralities of equipment for conveying chemicals are interconnected in accordance with a chosen operation of a process or apparatus. A separate information carrier corresponds to each piece of equipment of the first plurality and a control unit corresponds to each piece of the second plurality. The interlock system establishes an appropriate set of operating parameters for the chosen operation when the information carrier which corresponds to the interconnected first piece of equipment engages the control unit corresponding to the interconnected second piece of equipment.
