The CPX system is a distributed I/O/P platform designed to interface to fieldbus systems, providing a wide variety of inputs, outputs and pneumatics, allowing machine builders and users to reduce their number of automation suppliers while maintaining performance and reliability, lowering both initial cost and total life-cycle cost. Proportional pneumatic modules include the VPPM (an integrated proportional pressure regulator with internal pressure sensors, and dedicated analog I/O card); the 4AE-P (a 4-channel integrated pressure sensor module with built-in pneumatic ports); and the MPA-P (a single channel pressure sensor module, designed to monitor the supply pressure of pneumatic valves, if chosen). These modules are freely combinable within the basic CPX system.