(forward compatible library) A forward compatible library is developed in such a way that its functionalities are forward compatible. This means that every version of a forward compatible library contains all functionalities of the previous version and a newer library version can be easily used in already existing projects without any changes.
A programming unit that has 1 or more inputs and returns 1 or more outputs. FBs are called through an instance (function block copy with dedicated name and variables) and each instance has a persistent state (outputs and internal variables) from 1 call to the other.
Examples: timers, counters
The index of the ARRAY.
(Internet protocol Part of the TCP/IP protocol family that tracks the Internet addresses of devices, routes outgoing messages, and recognizes incoming messages.
(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.
(transport layer security) A protocol for encrypted data transfer. Successor of SSL.
