1766-RM001A-EN-P MicroLogix 1400 Programmable Controllers ...

670 Glossaryfull-duplexA mode of communication where data may be transmitted and receivedsimultaneously (contrast with half-duplex).half-duplexA mode of communication where data transmission is limited to onedirection at a time.hard diskA storage device in a personal computer.high byteBits 8 to 15 of a word.housekeepingThe portion of the scan when the controller performs internal checks andservices communications.input deviceA device, such as a push button or a switch, that supplies an electricalsignal to the controller.input scanThe controller reads all input devices connected to the input terminals.inrush currentThe temporary surge of current produced when a device or circuit isinitially energized.instructionA mnemonic defining an operation to be performed by the processor. Arung in a program consists of a set of input and output instructions. Theinput instructions are evaluated by the controller as being true or false. Inturn, the controller sets the output instructions to true or false.instruction setThe set of instructions available within a controller.Publication 1766-RM001A-EN-P - October 2008