ABSTRACT
Computer systems also have on-line compilers and off-line compilers. This means that, while the system is actively monitoring or controlling process routines, the engineer or programmer may at the same time modify his control scheme or compile new scan-and-alarm-logging programs. Instructions enter the machine through some type of input equipment. The input equipment would normally be used to convert these instructions into electrical pulses that would represent the data. An important component is the support software, called the compiler. The compiler converts the language employed by the engineer or programmer into machine language the computer can understand. The Foxboro Control Package (FCP) refers to the computer equivalent of an individual analog device as a "block." For every analog "black box," there is an equivalent computer "block." FCP consists of standard control blocks that provide a wide range of process monitoring, control, and calculation functions. Each FCP Control Package block is a standard skeletal definition of one process function.
