Instruction list

Instruction List (IL) is one of the 5 languages supported by the IEC 61131-3 standard. It is designed for programmable logic controllers (PLCs). It is a low level language and resembles assembly. All of the languages share IEC61131 Common Elements. The variables and function call are defined by the common elements so different languages can be used in the same program.

Program control (control flow) is achieved by jump instructions and function calls (subroutines with optional parameters).

The file format has now been standardized to XML by PLCopen.


         LD     Speed
         GT     2000
         JMPCN  VOLTS_OK
         LD     Volts
         ST     %Q75

Variations from IEC 61131

Many vendors whilst incorporating the full IEC 61131-3 requirements have additional vendor specific calls/function blocks to suit their hardware such as reading or writing to I/O. Siemens PLC instruction list language is known as "Statement List" or "STL" in English, and "Anweisungs-Liste" or "AWL" in German, Italian and Spanish. The user of a Simatic development package may choose between German and International mnemonics to represent instructions. For example, "A" for "AND" or "U" for "UND", "I" for "Input" or "E" for "Eingang".

See also

External links

1-bit architecture

A 1-bit computer architecture is an instruction set architecture for a processor that has datapath widths and data register widths of 1 bit (1/8 octet) wide.

An example of a 1-bit computer built from discrete logic SSI chips were the Wang 700 (1968/1970) and Wang 500 (1970/1971) calculator as well as the Wang 1200 (1971/1972) word processor series of Wang Laboratories.

An example of a 1-bit architecture that was marketed as a CPU is the Motorola MC14500B Industrial Control Unit (ICU), introduced in 1977 and manufactured at least up into the mid 1990s. One of the computers known to be based on this CPU was the WDR 1-bit computer. A typical sequence of instructions from a program for a 1-bit architecture might be:

load digital input 1 into a 1-bit register;

OR the value in the 1-bit register with input 2, leaving the result in the register;

write the value in the 1-bit register to output 1.This architecture was considered superior for programs making decisions rather than performing arithmetic computations, for ladder logic as well as for serial data processing.There are also several design studies for 1-bit architectures in academia, and corresponding 1-bit logic can also be found in programming.

Other examples of 1-bit architectures are programmable logic controllers (PLCs), programmed in instruction list (IL).

Several early massively parallel computers used 1-bit architectures for the processors as well. Examples include the Goodyear MPP and the Connection Machine. By using a 1-bit architecture for the individual processors a very large array (e.g.: the Connection Machine had 65,536 processors) could be constructed with the chip technology available at the time. In this case the slow computation of a 1-bit processor was traded off against the large number of processors.

1-bit CPUs can meanwhile be considered obsolete, not many kinds have been produced and none are known to be available in the major computer component stores (as of 2019, a few MC14500B chips are still available from brokers for obsolete parts.).

Atmel AVR instruction set

The Atmel AVR instruction set is the machine language for the Atmel AVR, a modified Harvard architecture 8-bit RISC single chip microcontroller which was developed by Atmel in 1996. The AVR was one of the first microcontroller families to use on-chip flash memory for program storage.


An awl is a long, pointed spike tool. It may be a:

Bradawl, a tool for making holes in wood

Scratch awl, a tool used for marking wood

Stitching awl, a tool for piercing holes in leatherAwl, AWL and similar may also refer to:

Ahlspiess or Awl pike, a polearm

AA-4 'Awl', the NATO reporting name for the Raduga K-9 air-to-air missile

Absence Without Leave

Academic Word List

Aircraft warning light

Alliance for Workers' Liberty, a Trotskyist group in Britain

Arizona Winter League, baseball

Awl butterflies, the genus Hasora and some members of the subfamily Coeliadinae

Awl-flies, the true fly family Xylophagidae

The Awl, a current events and culture website

Anweisungsliste (a.k.a. Statement List), instruction list programming language for Siemens SIMATIC S7


Befunge is a stack-based, reflective, esoteric programming language. It differs from conventional languages in that programs are arranged on a two-dimensional grid. "Arrow" instructions direct the control flow to the left, right, up or down, and loops are constructed by sending the control flow in a cycle. It has been described as "a cross between Forth and Lemmings."

A worthy companion to INTERCAL; a computer language family which escapes the quotidian limitation of linear control flow and embraces program counters flying through multiple dimensions with exotic topologies.

Function block diagram

The Function Block Diagram (FBD) is a graphical language for programmable logic controller design, that can describe the function between input variables and output variables. A function is described as a set of elementary blocks. Input and output variables are connected to blocks by connection lines.

Inputs and outputs of the blocks are wired together with connection lines, or links. Single lines may be used to connect two logical points of the diagram:

An input variable and an input of a block

An output of a block and an input of another block

An output of a block and an output variableThe connection is oriented, meaning that the line carries associated data from the left end to the right end. The left and right ends of the connection line must be of the same type.

Multiple right connection, also called divergence can be used to broadcast information from its left end to each of its right ends. All ends of the connection must be of the same type.

Function Block Diagram is one of five languages for logic or control configuration supported by standard IEC 61131-3 for a control system such as a Programmable Logic Controller (PLC) or a Distributed Control System (DCS). The other supported languages are ladder logic, sequential function chart, structured text, and instruction list.

Hitachi 6309

The 6309 is Hitachi's CMOS version of the Motorola 6809 microprocessor. While in "Emulation Mode" it is fully compatible with the 6809. To the 6809 specifications it adds higher clock rates, enhanced features, new instructions, and additional registers. Most new instructions were added to support the additional registers, as well as up to 32-bit math, hardware division, bit manipulations, and block transfers. The 6309 is generally 30% faster in native mode than the 6809.

Surprisingly, this information was never published by Hitachi. The April 1988 issue of Oh! FM, a Japanese magazine for Fujitsu personal computer users, contained the first description of the 6309's additional capabilities. Later, Hirotsugu Kakugawa posted details of the 6309's new features and instructions to comp.sys.m6809. This led to the development of NitrOS9 for the Tandy Color Computer 3.

IEC 61131-3

IEC 61131-3 is the third part (of 10) of the open international standard IEC 61131 for programmable logic controllers, and was first published in December 1993 by the IEC. The current (third) edition was published in February 2013.

Part 3 of IEC 61131 deals with basic software architecture and programming languages of the control program within PLC. It defines three graphical and two textual programming language standards:

Ladder diagram (LD), graphical

Function block diagram (FBD), graphical

Structured text (ST), textual

Instruction list (IL), textual (deprecated in 3rd edition of the standard)

Sequential function chart (SFC), has elements to organize programs for sequential and parallel control processing, graphical.

Industrial control system

Industrial control system (ICS) is a general term that encompasses several types of control systems and associated instrumentation used for industrial process control.

Such systems can range from a few modular panel-mounted controllers to large interconnected and interactive distributed control systems with many thousands of field connections. All systems receive data received from remote sensors measuring process variables (PVs), compare these with desired set points (SPs) and derive command functions which are used to control a process through the final control elements (FCEs), such as control valves.

The larger systems are usually implemented by Supervisory Control and Data Acquisition (SCADA) systems, or distributed control systems (DCS), and programmable logic controllers (PLCs), though SCADA and PLC systems are scalable down to small systems with few control loops. Such systems are extensively used in industries such as chemical processing, pulp and paper manufacture, power generation, oil and gas processing and telecommunications.

Ladder logic

Ladder logic was originally a written method to document the design and construction of relay racks as used in manufacturing and process control. Each device in the relay rack would be represented by a symbol on the ladder diagram with connections between those devices shown. In addition, other items external to the relay rack such as pumps, heaters, and so forth would also be shown on the ladder diagram.

Ladder logic has evolved into a programming language that represents a program by a graphical diagram based on the circuit diagrams of relay logic hardware. Ladder logic is used to develop software for programmable logic controllers (PLCs) used in industrial control applications. The name is based on the observation that programs in this language resemble ladders, with two vertical rails and a series of horizontal rungs between them. While ladder diagrams were once the only available notation for recording programmable controller programs, today other forms are standardized in IEC 61131-3 (For example, as an alternative to the graphical ladder logic form, there is also a more assembly language like format called Instruction list within the IEC 61131-3 standard.).

List of Governors of North Dakota

The Governor of North Dakota is the chief executive of the U.S. state of North Dakota. The current Governor is Doug Burgum. The Governor has the power to sign or veto laws, and to call the Legislative Assembly into emergency session. The Governor is also chairman of the North Dakota Industrial Commission. He has an ex officio North Dakota Governor's Residence. There are no limits on the number of terms a governor may serve.

The following is a list of Governors of the state of North Dakota, United States.

List of school districts in Wisconsin

This is a complete list of school districts in the state of Wisconsin.


PLCopen is an independent organisation providing efficiency in industrial automation based on the needs of users. PLCopen members have concentrated on technical specifications around IEC 61131-3, creating specifications and implementations in order to reduce cost in industrial engineering. The outcome for example is standardized libraries for different application fields, harmonized language conformity levels and engineering interfaces for exchange. Experts of the PLCopen members are organized in technical committees and together with end users define such open standards.

PLCopen was founded in 1992 just after the world wide programming standard IEC 61131-3 was published. The controls market at that time was a very heterogeneous market with different types of programming methods for many different PLCs. The IEC 61131-3 is a standard defining the programming languages for PLCs, embedded controls, and industrial PCs, harmonizing applications independent from specific dialects, but still based on known methods such as the textual programming languages Instruction List, and Structured Text, the graphical programming languages Function Block Diagram and Ladder Diagram (a.k.a. Ladder logic), and the structuring tool Sequential Function Chart.

Today, IEC 61131-3 is a highly accepted programming standard and many industrial software and hardware companies offer products based on this standard, which in the end are used in many different machinery and other application fields.

Current topics are:

Motion control and

Safety functionality

XML data exchange format standardizing the base data of IEC projects in software systems, as used for instance by AutomationML

Benchmarking projects in order to have a good sophisticated benchmark standard.

And in the field of communication PLCopen has developed together with OPC Foundation the mapping of the IEC 61131-3 software model to the OPC Unified Architecture information model.

Peerless Lake, Alberta

Peerless Lake is an unincorporated community in northern Alberta, Canada. It is located on the northeastern shore of Peerless Lake, approximately 70 kilometres (43 mi) northeast of Red Earth Creek, and has an elevation of 695 metres (2,280 ft).

The community is under the jurisdiction of the Municipal District of Opportunity No. 17 and is located in the federal riding of Fort McMurray-Athabasca.

Programmable logic controller

A programmable logic controller (PLC) or programmable controller is an industrial digital computer which has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, or robotic devices, or any activity that requires high reliability control and ease of programming and process fault diagnosis.

PLCs were first developed in the automobile manufacturing industry to provide flexible, ruggedized and easily programmable controllers to replace hard-wired relays, timers and sequencers. Since then, they have been widely adopted as high-reliability automation controllers suitable for harsh environments. A PLC is an example of a "hard" real-time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result.


Supervisory Control and Data Acquisition (SCADA) is a control system architecture that uses computers, networked data communications and graphical user interfaces for high-level process supervisory management, but uses other peripheral devices such as programmable logic controller (PLC) and discrete PID controllers to interface with the process plant or machinery.

The use of SCADA has been also considered for management and operations of project-driven-process in construction.


Seodang were private village schools providing elementary education during the Goryeo and Joseon dynasties of Korea.

Tony Evers

Anthony Steven Evers () (born November 5, 1951) is an American politician and educator who has been serving as the 46th Governor of Wisconsin, since January 7, 2019. A member of the Democratic Party, Evers previously served as the Wisconsin Superintendent of Public Instruction.Born and raised in Plymouth, Wisconsin, Evers was educated at the University of Wisconsin–Madison, eventually receiving a Ph. D. After working as a school teacher for several years, he became a school administrator, serving as a principal and, later, district superintendent. Evers first ran for Superintendent of Public Instruction in 1993 and 2001, losing both elections. However, he was appointed the deputy superintendent, a position he served in from 2001 to 2009. In 2009, he made another attempt for Superintendent of Public Instruction, this time winning. He was reelected twice, in 2013 and 2017.

Evers announced on August 23, 2017, that he would be a candidate for governor of Wisconsin, challenging two-term Republican incumbent Scott Walker. Walker was seen as a vulnerable incumbent and had been criticized for his policies regarding education. Evers won the Democratic primary in August 2018. Former state representative Mandela Barnes won the primary for lieutenant governor, becoming Evers' running mate. The pair defeated Walker in the general election.


UCBLogo, also known as Berkeley Logo, is closest to a de facto standard Logo programming language with its facilities for handling lists, files, I/O, and recursion in scripts, and can be used to teach most computer science concepts, as UC Berkeley lecturer Brian Harvey did in his Computer Science Logo Style trilogy.

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