Of Operation 2

DCS See Distributed Control System.


DD See Device Description.


DDL See Device Description Language.

Device Description
A program file written in the HART Device Description Language (DDL) that contains an electronic description of all of a device’s parameters and functions needed by a host application to communicate with the device

Device Description Language
A standardized programming language used to write DDs for HART-compatible field devices

Distributed Control System
Instrumentation (input/output devices, control devices, and operator interface devices) that permits transmission of control, measurement, and operating information to and from user-specified locations, connected by a communication link

Field
The area of a process plant outside the control room where measurements are made, and to and from which communication is provided; a part of a message devoted to a particular function (e.g., the address field or the command field)

Field Device
A device generally not found in the control room; field devices may generate or receive an analog signal in addition to the HART digital communication signal

Frequency Shift Keying
Method of modulating digital information for transmission over paths with poor propagation characteristics; can be transmitted successfully over telephone systems

FSK See Frequency Shift Keying.

Gateway
A network device that enables other devices on the network to communicate with a second network using a different protocol