Glossary

D

DST

(daylight saving time) Is the practice of advancing clocks during summer months so that evening daylight lasts longer, while sacrificing normal sunrise times. Regions that use daylight saving time adjust clocks forward one hour in the spring and adjust them backward in the autumn to standard time.

E

Ethernet

A physical and data link layer technology for LANs, also known as IEEE 802.3.

G

GVL

(global variable list) Manages global variables within an EcoStruxure Machine Expert project.

M

MAST

A processor task that is run through its programming software. The MAST task has 2 sections:

oIN: Inputs are copied to the IN section before execution of the MAST task.

oOUT: Outputs are copied to the OUT section after execution of the MAST task.

P

POU

(program organization unit) A variable declaration in source code and a corresponding instruction set. POUs facilitate the modular re-use of software programs, functions, and function blocks. Once declared, POUs are available to one another.

R

RTC

(real-time clock) A battery-backed time-of-day and calender clock that operates continuously, even when the controller is not powered for the life of the battery.

S

SNTP

(simple network time protocol) A simplified version of the NTP (network time) protocol. It is used to synchronize computer clock times in a network of computers. It uses Coordinated Universal Time (UTC) to synchronize computer clock times to a millisecond, and sometimes to a fraction of a millisecond.

U

UNIX

Time format represents the seconds elapsed since 01/01/1970 - 00:00:00.

UTC

(universal time coordinated) The primary time standard by which the world regulates clocks and time.