Introductory Remarks: DDP vs. DCC

Abstract

Publisher Summary This chapter describes the comparison of distributed computer control (DDC) and distributed data processing (DDP) systems. Great similarities can be identified in the DDC and DDP systems. In a hierarchical architecture, there is a large central processor that handles all communication and coordination among a set of local processors.In a decentralized architecture, there is a communications network interconnecting a number of local processors, and the management and coordination functions are also decentralized. The timescale of the local process determines the required bandwidth of the controller, and the ways that the local process interacts with the rest of the plant is well-defined. The type of information required from other parts of the plant and the frequency with which it must be updated, are also reasonably well defined. If the interconnecting structure of the overall physical plant can be modified at all, the number of possible modifications is usually finite and they are not frequently made.