Technical terms explained easily

The glossary contains technical terms and keywords from the field of automation technology. To search for a term, we recommend using the browser's own search with the shortcut Ctrl + F or Cmd + F.



ACCON: Acronym for access and control, refering to access a controller respectively to access and control a controller and its information. More information about ACCON can be found here.

adapter: Piece of hardware to adjust a connection, e.g. because of different connectors and/or a needed signal conversion. For software this is called wrapper.

alarm: Warning or notification regarding a defined situation or an occurred condition. These are usually undesirable or dangerous situations. In remote maintenance, for example, an alarm modem can be used for this purpose.

alarm modem: Modem that sends a message in case of a defined situation, e.g. an alarm has been set up by the user should the temperature exceed a certain value. As soon as this occurs, the modem sends a message (SMS, e-mail, etc.) with the defined text to one or more predefined recipients.

ALS: Abbreviation from German Arburg Leitrechner-System, the host computer system from the company Arburg, a production management system (more precisely MES) for injection moulding production.

automate: The action of automation. But also the interaction of measuring and controlling to achieve a target value, i.e. a specific target value that has been defined. This is then checked by measuring. If the actual value deviates from the target value, the control is carried out accordingly, i.e. a targeted influence takes place. An example from everyday life is the air conditioning of a car, where a target temperature is set in degrees. Instead of using the word automate, people often refer to this as control. The difference between controlling and automating can be distinguished by asking if, after setting the goal, human interaction is needed (control) or not (automate).

automation: Automatic operation of a system, usually of automatic machines, to achieve a goal more efficiently, e.g. hazard minimization, efficiency increase, scrap reduction. The main components are measuring, controlling and automating, often referred to as instrumentation and control engineering (ICE).

automation technology: A branch of engineering science that deals with automation, i.e. technology that helps or supports automation. Automation technology mainly concerns the fields of plant construction, electrical engineering and mechanical engineering.


backup: Saving a current data status to prevent data loss. In case of data loss, the backup can be restored to the production system and the system/user can continue working with the previously saved data.


client: Software program that is executed within a network on an end device (e.g. a PC) and uses the services of a server.

CODESYS: Formerly CoDeSys; acronym for Controller Developer System; a manufacturer-independent automation software for the project planning of control systems (development environment for PLCs) from the company of the same name (formerly 3S).

control: Influencing a manipulated variable of a machine or system. In the case of binary variables, this can mean on or off. An everyday example of this is a classic radiator where one directly controls the temperature manually by opening or closing the hot water supply. Often also used instead of the word automate.

controller: Also called control or control unit. Controllers are usually electronic units used to control certain processes. Most frequently used are hardware controllers. However, there are also pure software controllers (see also Soft PLC).

cylce: PLC programs consist of a piece of code that is re-executed after a complete run is completed. A single execution or each single repetition is called a cycle. In general, the code of a PLC program is executed again and again like a continuous loop.

cycle-precise: Sampling, i.e. the recording of measured values, after each cycle or at the end of each run of a PLC program. An alternative possibility is the polling-precise sampling.


DLCS: Abbreviation for the VPN service DELTA LOGIC Connectivity Service

data collection: also data acquisition; Recording of data, which are usually determined by measuring physical quantities. These data are stored in the appropriate chronological order and usually provided with a time stamp. In automation technology, the recording of specific measured variables is normally repeated at regular intervals in order to be able to react to changes, for example, to be able to track quality fluctuations in the manufactured products.

data logger: Software for logging data, such as ACCON-EasyLog. A data logger records certain values at regular intervals and storages them. These can later be read out, evaluated, further processed or graphically displayed.

data logging: Recording data at specific time intervals and over a period of time. For example, reading the temperature every second during the production period. This can help to prove assured high quality later on.


EDGE: Abbreviation for Enhanced Data Rates for GSM Evolution; 2nd generation mobile radio standard, also 2G; EDGE extends the GSM standard by higher data transmission rates.


FBD: Abbreviation for Function Block Diagram, a graphically oriented language for creating PLC programs.

Fieldbus: Bus system for communication between field devices (e.g. sensors) and automation devices such as controllers.


GSM: Abbreviation for Global System for Mobile Communications; mobile radio standard for fully digital mobile radio networks (telephony, short messages and data), introduced in 1990. An extension of the GSM standard is EDGE.


host: Often short for host computer; A computer within a network that provides services to others.

HPSA: Abbreviation for High Speed Packet Access; extension of the UMTS mobile communications standard (3G) to include higher data transmission rates.


IIoT: Abbreviation for Industrial Internet of Things. This is about the digitalization of industrial production through intelligent networking throughout the entire value chain. The German denomination is Industrie 4.0 (lit. Industry 4.0).

IL: Abbreviation for Instruction List, an assembler-like language for programming PLCs. An alternative name for this is STL.

industrial router: Router suitable for industrial use. Compared to normal routers, industrial routers are usually characterized by particularly robust hardware and usually offer additional features on the software side.

Industrie 4.0/Industry 4.0: German denomination for IIoT. By using the version number 4.0, which is typical for software products, it is intended to indicate that this is the fourth industrial revolution.

interface: An interface is the point of contact between two different components (hardware or software) to exchange information (data or control signals).

Internet of Things: The Internet of Things (IoT) connects the virtual world and physical objects. In everyday life, devices that support this are often supplemented with the adjective smart or intelligent, e.g. a smart refrigerator or a intelligent toaster. In the industrial environment IoT is referred to as IIoT (Industrial Internet of Things) or Industry 4.0.

Internet router: Is a router that connects a network, e.g. a LAN or WLAN, to the Internet and thus enables Internet access for devices within the network.

IoT: Abbreviation for Internet of Things, the connection of physical and virtual world.


LAN: Abbreviation for Local Area Network

LD/LAD: Abbreviation for Ladder Diagram, a graphical programming language for PLCs, which is based on the style of circuit diagrams.

LTE: Abbreviation for Long Term Evolution; fourth generation mobile radio standard, also known as 4G. LTE offers higher download rates than previous mobile radio standards such as GSM, EDGE and UMTS.

LTE router: Mobile router that uses the LTE network for Internet access.


M2M: Abbreviation for Machine to Machine communication, the automated exchange of information between end devices

measure: Determination of a physical quantity, such as temperature, density, pressure, length

MES: Abbreviation for Manufacturing Execution System is a system for production control that links business planning with the production level and makes use of the connection. Other terms for this are Production Management System (PMS) or Production Control System.

mobile router: Also cellular router; Internet-capable router that uses the mobile radio network for Internet access, e.g. GSM, EDGE, UMTS or LTE.


OPC: Abbreviation for Open Platform Communications; Describes a standard for data exchange. This allows software programs from different manufacturers in the field of automation technology to communicate with each other using the defined interface. The OPC Foundation, which is responsible for the standard, develops and maintains the OPC standard. There are different specifications for different use cases, e.g. OPC DA and OPC UA. The implementation is based on the client-server model, i.e. there is an OPC server that converts the data of the actual sources according to the OPC specification and OPC clients that query these data from the OPC server.

OPC client: Uses the data of an OPC server. For this purpose the OPC client only has to know the used OPC interface. It does not have to know other protocols of the actual data source, e.g. an S5 PLC. This conversion work is done by the OPC server.

OPC DA: Abbreviation for Open Platform Communications Data Access; an OPC specification for the transmission of real-time values based on DCOM. Alternatively, there is OPC XML-DA, which is based on XML. The newer, platform-independent OPC specification is called OPC UA.

OPC server: Provides data according to an OPC specification, e.g. OPC UA or OPC DA. For this purpose the OPC server converts the data of the original data source, e.g. an S7 controller, and then makes it available to the OPC clients according to the OPC specification used.

OPC UA: Abbreviation for Open Platform Communications Unified Architecture; Latest OPC standard for platform-independent exchange with SOA. Offers significantly more features than its various predecessors, such as OPC DA.


PB: Abbreviation for PROFIBUS

PG: German abbreviation for Programmier-Gerät (literally a programming device), a device for programming (creating and editing programs), also called a programmer. At the beginning of the development of PLCs this was mostly mobile and robust hardware in case size. Nowadays these are often smaller devices like laptops, tablets or handheld PCs.

PLC: Abbreviation for Programmable Logic Controller. These controllers control devices or systems. The desired sequence is determined with the help of a digital PLC program. In the predecessor of the PLC, the so-called relay logic, the programs were generated by fixed hardware wiring. Instead of physical hardware PLCs, nowadays there are also software-based controllers. These are called software controller or Soft PLC.

PLC program: Program that controls the execution of a PLC. Usually one of the following programming languages is used to create the programs: IL or STL, LD, FBD, SFC or ST.

PN: Abbreviation for PROFINET

polling-precise: Sampling, i.e. the recording of measured values after a defined time interval. This way the sampling isn't defined by the cycles but only by the defined time interval. When reading out the values the execution of the PLC program could be at any point. Alternatively, the sampling can also be carried out cycle-precise.

production control system: Other term for production management system, a system for production control that links business planning with the production level and makes use of this connection. The more common term is MES.

production management system: Process-oriented level of a multi-layer production management system that links business planning with the production level. Other term for production control system. The more common term is MES.

PROFIBUS: Acronym for Process Field Bus; is a field bus communication standard in automation technology. It can be used to implement decentralized, manufacturer-independent bus communication. PROFIBUS is part of the international standard IEC 61158. Its successor is PROFINET.

PROFINET: Acronym for Process Field Network; open Industrial Ethernet standard via TCP/IP and IT standards for automation. This allows different levels to communicate in real time via decentralized peripherals. PROFINET is the successor to PROFIBUS.

programming device: A device for programming (creating and editing programs), also called a programmer or PG (from German Programmiergerät).


remote access: Access from a distance to IT systems, often to assist third parties or for remote maintenance purposes. This can be, for example, the direct control of a remote PC via Remote Desktop.

remote control: Remote influence on and control of machines, devices and other equipment

remote maintenance: Remote access to IT systems for maintenance or repair purposes, i.e. one is not directly on site, but accesses the corresponding IT system e.g. via a VPN connection.

restore: Recovering an old data status from a backup

router: Also network router; responsible for the assignment of data packets between different computer networks. The most frequently used routers in private environments are Internet routers. These connect the local network with the Internet. For the industrial use there are special industrial routers. In addition, there are VPN routers of various types for different requirements, e.g. WLAN routers or mobile routers such as UMTS routers and LTE routers.

routing: Forwarding of data packets or path finding for message transmission in computer networks. Routing is an important basis for connecting different computer networks, such as the Internet. Data packets are usually forwarded from the sender via several routers until they reach the recipient.


S5: Controller family of SIMATIC PLCs from the manufacturer Siemens. The current generation of Siemens SIMATIC PLCs is called S7.

S7: Controller family of SIMATIC PLCs from the manufacturer Siemens. These include the older S7-200, S7-300, S7-400 series as well as the newer S7-1200 and S7-1500 series, the predecessor generation of S7 PLCs being called S5.

S7-compatible PLC: PLC that can be used instead of a Siemens S7 because it has the same range of functions, e.g. from Vipa, Saia, Berthel or also in the form of a Soft PLC, such as ACCONtrol.

sampling: In signal processing, measured values are read out. Recording or reading out is called sampling. This sampling takes place at a specifically defined point in time. There are two different approaches of sampling, polling-precise and cycle-precise.

SCL: Abbreviation for Structured Control Language, a form of the Pascal-like programming language ST (Structured Text) for Siemens S7 PLCs

server: Software program that provides a specific service to clients. The computer on which the server is installed is called host. Usually, the host computer is therefore also referred to as a server.

SFC: Abbreviation for Sequential Function Chart, a graphical language for programming PLCs based on Petri nets.

SIMATIC: Product name of the company Siemens in the sense of a complete product complex or system. This includes products from the fields of automation technology, control technology and production control system (MES).

Soft PLC: Also software PLC; alternative to the classic hardware PLC in the form of a piece of software that emulates the functionality of a physical PLC or takes over its tasks. An example for a Soft PLC is ACCONtrol, which is command conform to a Siemens S7-416.

software controller: A controller in software form in contrast to the classic hardware controller. An example for these are Soft PLCs.

ST: Abbreviation for Structured Text, a text-based Pascal-like language for programming PLCs. The Siemens variant for S7 controllers is called SCL.

STL: Abbreviation for Statement List, an Assembler-like form of presentation of PLC programs. The name STL is usually used for Siemens' own display format. A more general term is Instruction List (IL).

STEP 5: Sometimes STEP5; programming software from Siemens for SIMATIC S5 controllers

STEP 7: Sometimes STEP7; programming software from Siemens for SIMATIC S7 controllers


TIA: Abbreviation for Totally Integrated Automation, a Siemens term for the organizational concept of an automation solution that extends along the entire value chain. TIA is also often used colloquially as an abbreviation for TIA Portal.

TIA Portal: TIA Portal is a software solution from Siemens that implements the functionality of the TIA concept.


UMTS: Abbreviation for Universal Mobile Telecommunications System; 3rd generation mobile radio standard, also called 3G; UMTS enables higher data transmission rates than GSM or EDGE. An extension of UMTS is HSPA.

UMTS router: Mobile router that uses the UMTS network for Internet access.


VPN: Abbreviation for Virtual Private Network; a virtual (as opposed to a physical network or connection), private, i.e. self-contained, communications network. This means that an existing communications network is used as a transport medium. Remote users can thus access or participate in a local network as if they were directly on site. The connections for data transmission are usually encrypted.

VPN portal: Other name for VPN service

VPN router: VPN-capable router, i.e. a router that enables the integration of remote subscribers into a network or access to the local network from outside.

VPN service: Is a service of a service provider that offers the functionality of a VPN. I.e. with the help of the provider's software, a VPN connection can be established to a defined point.


WAN: Abbreviation for Wide Area Network, i.e. in contrast to LAN (Local Area Network) a spatially extended network. The network can extend over countries or continents. The number of computers or LANs that can be networked is very high and limited by the number of maximum possible IP addresses.

WLAN: Often also referred to as WiFi; Abbreviation for Wireless Local Area Network is a local radio network. This is usually achieved with a WLAN router. Here the router is directly connected by cable to another network and then enables wireless use or access to this other network via a radio signal.

WLAN router: WLAN-enabled router, i.e. a router that connects a wireless local network with another network.

wrapper: A wrapper is an interface that surrounds another, already existing interface (comparable to a hardware adapter). This is used for example if the original interface is written in a different programming language than the one you need. The wrapper emulates the interface in the required programming language. Internally the wrapper calls the original interface and converts the input and output of the function calls appropriately.