A field-mounted process device (116) with multiple isolated connections (56, 58, 60, 62) includes a connection that can be an input or an output . The given input or output can couple to multiple sensors or actuators, respectively. The process device (116) can be wholly powered through its communication I/O port (122) . The process device includes a controller (40) adapted to measure one or more characteristics of sensors coupled to an input connection and to control actuators coupled to an output connection. The controller (40) can be further adapted to execute a user generated control algorithm relating process input information with process output commands .