An apparatus for controlling a valve including an enclosure that defines first and second chambers, an indicator proximate the first and second chambers, an operating media distribution system that is disposed in the first chamber, and an electronic control unit disposed in the second chamber. The operating media distribution system includes a manifold block that has an exterior surface, and a plurality of operating media distribution cartridges exchangeably disposed with respect to the manifold block. The manifold block defines a plurality of holes, an operating media supply passage and an operating media exhaust passage. Each of the plurality of operating media distribution cartridges is disposed in a respective one of the plurality of holes and includes a cylinder and a spool assembly that is disposed in and displaced relative to the cylinder. The electronic control unit operates at least one electromagnetic valve to control operating media flow via the operating media distribution system.