A program including configuration data, symbols, and documentation.
A type that is encoded in an 8-bit format, ranging from 00 hex to FF hex.
(continuous function chart) A graphical programming language (an extension of the IEC 61131-3 standard) based on the function block diagram language that works like a flowchart. However, no networks are used and free positioning of graphic elements is possible, which allows feedback loops. For each block, the inputs are on the left and the outputs on the right. You can link the block outputs to the inputs of other blocks to create complex expressions.
The arrangement and interconnection of hardware components within a system and the hardware and software parameters that determine the operating characteristics of the system.
(function block) A convenient programming mechanism that consolidates a group of programming instructions to perform a specific and normalized action, such as speed control, interval control, or counting. A function block may comprise configuration data, a set of internal or external operating parameters and usually 1 or more data inputs and outputs.
(frequency generator) A function that generates a square wave signal with programmable frequency.
(frequency generator) A function that generates a square wave signal with programmable frequency.
A programming unit that has 1 input and returns 1 immediate result. However, unlike FBs, it is directly called with its name (as opposed to through an instance), has no persistent state from one call to the next and can be used as an operand in other programming expressions.
Examples: boolean (AND) operators, calculations, conversions (BYTE_TO_INT)
One of the 5 languages for logic or control supported by the standard IEC 61131-3 for control systems. Function block diagram is a graphically oriented programming language. It works with a list of networks where each network contains a graphical structure of boxes and connection lines representing either a logical or arithmetic expression, the call of a function block, a jump, or a return instruction.
(identifier/identification)
Part 3 of a 3-part IEC standard for industrial automation equipment. IEC 61131-3 is concerned with controller programming languages and defines 2 graphical and 2 textual programming language standards. The graphical programming languages are ladder diagram and function block diagram. The textual programming languages include structured text and instruction list.
(instruction list) A program written in the language that is composed of a series of text-based instructions executed sequentially by the controller. Each instruction includes a line number, an instruction code, and an operand (refer to IEC 61131-3).
(integer) A whole number encoded in 16 bits.
(ladder diagram) A graphical representation of the instructions of a controller program with symbols for contacts, coils, and blocks in a series of rungs executed sequentially by a controller (refer to IEC 61131-3).
Consists of several functions and/or equipment.
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.
(millisecond)
Open loop control refers to a motion control system with no external sensors to provide position or velocity correction signals.
See also: closed loop.
(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.
The component of an application that consists of compiled source code capable of being installed in the memory of a logic controller.
(pulse train outputs) A fast output that oscillates between off and on in a fixed 50-50 duty cycle, producing a square wave form. PTO is especially well suited for applications such as stepper motors, frequency converters, and servo motor control, among others.
(pulse width modulation) A fast output that oscillates between off and on in an adjustable duty cycle, producing a rectangular wave form (though you can adjust it to produce a square wave).
A command that causes the controller to scan the application program, read the physical inputs, and write to the physical outputs according to solution of the logic of the program.
(structured text) A language that includes complex statements and nested instructions (such as iteration loops, conditional executions, or functions). ST is compliant with IEC 61131-3.
A command that causes the controller to stop running an application program.
A group of sections and subroutines, executed cyclically or periodically for the MAST task or periodically for the FAST task.
A task possesses a level of priority and is linked to inputs and outputs of the controller. These I/O are refreshed in relation to the task.
A controller can have several tasks.
A memory unit that is addressed and modified by a program.
