(American standard code for Information Interchange) A protocol for representing alphanumeric characters (letters, numbers, certain graphics, and control characters).
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.
A client is a part of a communications application. The initially active part establishes a connection (TCP) or sends data to the server.
(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.
(file transfer protocol) A standard network protocol built on a client-server architecture to exchange and manipulate files over TCP/IP based networks regardless of their size.
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.
(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.
The IP address of IPv4 (Internet Protocol version 4) is a value of 4 bytes which identifies the devices connected to an IP network.
(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).
(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.
A server is a part of a communications application. At first, the server is passive. It waits until clients initialize communication. A server runs on a defined port number and the clients know its address.
(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 memory unit that is addressed and modified by a program.
