Specifications

Table Of Contents
18 Chapter 2
Programming Command Guidelines
Getting Started with Programming Commands
Getting Started with Programming Commands
Understanding Common Terms
The following terms are used throughout the remainder of this chapter.
Controller A controller is any computer used to communicate with an
instrument. A controller can be a personal computer (PC), a
minicomputer, or a plug-in card in a card cage. Some intelligent
instruments can also function as controllers.
Program
Message A program message is a combination of one or more properly
formatted commands. Program messages always go from a
controller to an instrument. Program messages tell the
instrument how to make measurements and output signals.
Response
Message A response message is a collection of data in specific formats.
Response messages always go from an instrument to a
controller. Response messages tell the controller about the
internal state of the instrument and about measured values.
Command A command is an instruction. You combine commands to form
messages that control instruments. In general, a command
consists of mnemonics (keywords), parameters, and
punctuation.
Query A query is a special type of command. Queries instruct the
instrument to make response data available to the controller.
Query mnemonics always end with a question mark, ?.