Taco, Inc. (Cranston, RI ) says its PC600 Series of powerport cards can be used in conjunction with any of its expanded relay units to enhance total system integration and performance. By controlling the operation of the circulators attached to the switching relay, the PC600 cards are designed to provide energy savings, system protection, and an increased comfort level. Meanwhile, it says its PC7000 Series of add-on power controls are also designed to provide energy savings, system protection, and increase comfort control by regulating the supply water temperature to a heating system based on outdoor temperature by either controlling the boiler or injection pump.