According to the IEC standard, %I indicates a discrete input-type language object.

According to the IEC standard, %IW indicates an analog input-type language object.

According to the IEC standard, %M indicates a memory bit-type language object.

According to the IEC standard, %MW indicates a memory word-type language object.

According to the IEC standard, %Q indicates a discrete output-type language object.

According to the IEC standard, %QW indicates an analog output-type language object.

(address resolution protocol) A request and reply protocol used for resolution of network layer addresses into link layer addresses, a function in multiple-access networks.

A table containing elements of a single type.

The syntax is as follows: array [<limits>] OF <Type>

Example:

array [1..2] OF BOOL is a one-dimensional table with two elements of type BOOL.

array [1..10, 1..20] OF INT is a two-dimensional table with 10x20 elements of type INT.

(application response time) The time a PLC application takes to react to a given input. ART is measured from the time a physical signal in the PLC turns on and triggers a write command until the remote output turns on to signify that the data has been received.

(boolean type) The basic data type in computing. A BOOL variable can have either of the following two values: 0 (FALSE) or 1 (TRUE).

A bit extracted from a word is of type BOOL, for example: %MW10.4.

(bootstrap protocol) A UDP network protocol that can be used by a network client to automatically obtain an IP address from a server. The client identifies itself to the server using its MAC address. The server, which maintains a pre-configured table of client device MAC addresses and associated IP addresses, sends the client its defined IP address. The BOOTP service utilizes UDP ports 67 and 68.

A message sent to devices in the subnet.

(change configuration on the fly) A feature of Control Expert that allows a PLC hardware change in the system configuration while the PLC is operating and not impacting other active drop operations.

configured IED description: The SCL file that describes the communication-related part of an instantiated IED within a project. The communication section contains the address of the IED. The substation section related to this IED may be present and, if so, contains project-specific assigned name values.

Twisted pair cables

data attribute: A single piece of information.

instantiated data attribute: A single data attribute that has been assigned an initial value by the Modicon IEC 61850 Configuration Tool, thereby instantiating both the data attribute and its parent data object (DO).

A collection of data attributes and data objects that can be viewed and transmitted together. Although data sets are related to logical nodes, the member data attributes can originate in different logical nodes and logical devices. Data sets are used to define data collections that form the basis for reporting and logging using buffered report control blocks, unbuffered report control blocks, and GOOSE control blocks.

(derived data type) A set of elements with the same type (array) or with different types (structure).

derived data type: A derived data type is a set of elements with the same type (ARRAY) or with different types (structure).

For a defined application and architecture, the ability to predict that the delay between an event (change of an input value) and the corresponding change of an output state is a finite time t, smaller than the time required for your process to run correctly.

(derived function block) Function blocks that can be defined by the user in ST, IL, LD or FBD language.

(dynamic host configuration protocol) An extension of the BOOTP communications protocol that provides for the automatic assignment of IP addressing settings (including IP address, subnet mask, gateway IP address, and DNS server names). DHCP does not require the maintenance of a table identifying each network device. The client identifies itself to the DHCP server using either its MAC address, or a uniquely assigned device identifier. The DHCP service utilizes UDP ports 67 and 68.

(domain name server/service) A service that translates an alpha-numeric domain name into an IP address, the unique identifier of a device on the network.

data object: A single collection of one or more data attributes (DA).

instantiated data object: A single data object with one or more data attributes (DAs) that have been assigned an initial value by the Modicon IEC 61850 Configuration Tool.

An alpha-numeric string that identifies a device on the internet, and which appears as the primary component of a web site’s uniform resource locator (URL). For example, the domain name schneider-electric.com is the primary component of the URL www.schneider-electric.com.

Each domain name is assigned as part of the domain name system, and is associated with an IP address.

Also called a host name.

(dual-ring switch) A ConneXium extended managed switch with one of several possible predefined configurations downloaded to it so that it can participate in an Ethernet I/O network. A DRS provides 2 RSTP-enabled ring connections, one for the main ring and one for a sub-ring. It also manages QoS, which provides a predictable level of performance for both remote I/O and distributed I/O traffic on the same I/O network.

DRSs require a firmware version 6.0 or later.

The DT type is entered as follows:

DT#<Year>-<Month>-<Day>-<Hour>:<Minutes>:<Seconds>

(elementary function) A block used in a program to perform a predefined logical function.

A function does not have any information on the internal state. Several calls to the same function using the same input parameters will return the same output values. You will find information on the graphic form of the function call in the [functional block (instance)]. Unlike a call to a function block, function calls include only an output which is not named and whose name is identical to that of the function. In FBD, each call is indicated by a unique [number] via the graphic block. This number is managed automatically and cannot be modified.

Position and configure these functions in your program in order to execute your application.

You can also develop other functions using the SDKC development kit.

(elementary function block) A block used in a program to perform a predefined logical function.

EFBs have states and internal parameters. Even if the inputs are identical, the output values may differ. For example, a counter has an output indicating that the preselection value has been reached. This output is set to 1 when the current value is equal to the preselection value.

(enable) An optional block input. When enabled, an ENO output is set automatically.

If EN = 0, the block is not enabled; its internal program is not executed, and ENO is set to 0.

If EN = 1, the block's internal program is run and ENO is set to 1. If a runtime error is detected, ENO is set to 0.

If the EN input is not connected, it is set automatically to 1.

error notification The output associated with the optional input EN.

encoder, receiver, transmitter: ERT is a wireless protocol used to automatically read and transmit data from utility meters over a short range so utility personnel need not physically enter a premises and manually take readings from each meter.

A 10 Mb/s, 100 Mb/s, or 1 Gb/s, CSMA/CD, frame-based LAN that can run over copper twisted pair or fiber optic cable, or wireless. The IEEE standard 802.3 defines the rules for configuring a wired Ethernet network; the IEEE standard 802.11 defines the rules for configuring a wireless Ethernet network. Common forms include 10BASE-T, 100BASE-TX, and 1000BASE-T, which can utilize category 5e copper twisted pair cables and RJ45 modular connectors.

TCP/IP-based messaging for Modbus TCP . It is used for point-to-point, client/server messages that include both data (typically unscheduled information between a client and a server) and routing information.

(function block diagram) A graphical programming language that works like a flowchart. By adding simple logical blocks (AND, OR, etc.), each function or function block in the program is represented in this graphical format. For each block, the inputs are on the left and the outputs on the right. Block outputs can be linked to inputs of other blocks in order to create complex expressions.

(fast device replacement) A service that uses configuration software to replace an inoperable device.

(file transfer protocol) A protocol that copies a file from one host to another over a TCP/IP-based network, such as the internet. FTP uses a client-server architecture as well as separate control and data connections between the client and server.

The ability of 2 networked devices to independently and simultaneously communicate with each other in both directions.

A device that interconnects 2 different networks, sometimes with different network protocols. When used to connect networks based on different protocols, a gateway converts a datagram from one protocol stack into the other. When used to connect 2 IP-based networks, a gateway (also called a router) has 2 separate IP addresses, one on each network.

generic object-oriented substation event: A control model defined by the IEC61850 protocol that provides a mechanism for the transfer of event data relating to module status and value settings. GOOSE is a sub-set of the GSE model. As implemented in the Ethernet communication module, GOOSE is used to publish and subscribe to event data in the form of VLAN transmissions.

generic substation event: A control model defined by the IEC61850 protocol designed to provide event data transfers as multicast or broadcast transmissions.

Resistance to hydrocarbons, industrial oils, detergents and solder chips. Relative humidity up to 100%, saline atmosphere, significant temperature variations, operating temperature between - 10°C and + 70°C, or in mobile installations.

(human machine interface) An HMI is a device that displays process data to a human operator, who in turn uses the HMI to control the process.

An HMI is typically connected to a SCADA system to provide diagnostics and management data, such as scheduled maintenance procedures and detailed schematics for a particular machine or sensor.

A high-availability control system with a second (standby) PLC that maintains up-to-date system status. If the primary PLC becomes inoperable, the standby PLC takes control of the system.

(hypertext transfer protocol) A networking protocol for distributed and collaborative information systems. HTTP is the basis of data communication for the web.

IED capability description: A mandatory SCL file used to exchange data from the IED configurator to the system configurator. This file describes the functional and engineering capabilities of an IED type. It contains exactly one IED section for the IED type whose capabilities are described. The IED name shall be TEMPLATE.

(international electrotechnical commission) The agency that prepares and publishes international standards for electrical, electronic, and related technologies.

International standard: programmable logic controllers

Part 3: programming languages

intelligent electronic device: An IEC61850 protocol compliant, microprocessor based industrial device incorporating one or more processors with the capability of receiving or sending data/controls from or to an external source (for example, electronic multifunction meters, digital relays, controllers).

(internet group management protocol) This internet standard for multicasting allows a host to subscribe to a particular multicast group.

instantiated IED description: An SCL file that contains the configuration data for a single IED in an application. This file must contain the instantiated device description, communication settings, and data type templates. The file may optionally contain a description of LNs bound to the substation object.

(instruction list) A series of basic instructions similar to assembly language used to program processors. Each instruction is made up of an instruction code and an operand.

(integer) (encoded in 16 bits) The upper/lower limits are as follows: -(2 to the power of 15) to (2 to the power of 15) - 1.

Example:

-32768, 32767, 2#1111110001001001, 16#9FA4.

The 32-bit identifier, consisting of both a network address and a host address, assigned to a device connected to a TCP/IP network.

Jitter is the time variation in the delivery of an Ethernet packet, caused by packet queuing along its network travel path. Jitter can be reduced to predictable amounts by applying packet handling policies, e.g. quality of service (QoS), that grant priority to the packets of a specified type (e.g. remote I/O data packets) over other packet types.

(ladder diagram) A programming language that represents instructions to be executed as graphical diagrams very similar to electrical diagrams (contacts, coils, etc.).

logical device: A collection of a group of functions. Each function is defined as a logical node. A physical device can include one or more LDs. The IEC61850 server includes a root LD named System.

A value used to enter integer values in the decimal system. Values may be preceded by the "+" and "-" signs. Underscore signs (_) separating numbers are not significant.

Example:

-12, 0, 123_456, +986

logical node zero: A mandatory logical node (LN) of each LD.

logical node: A specific function of a logical device (LD), defined by a collection of data objects (DOs).

(management information base) A virtual database used for managing the objects in a communications network. See SNMP.

manufacturing message specification: A messaging system, defined by ISO 9506, that defines the process for the real-time transmission of industrial process data and control information among network devices and process control software.

An application-layer messaging protocol. Modbus provides client and server communications between devices connected on different types of buses or networks. Modbus offers many services specified by function codes.

(Modbus over TCP protocol) A Modbus variant used for communications over TCP/IP networks.

A special form of broadcast where copies of the packet are delivered to only a specified subset of network destinations.

(network time protocol) Protocol for synchronizing computer system clocks. The protocol uses a jitter buffer to resist the effects of variable latency.

(originator to target)

An Ethernet-based network containing operator tools (SCADA, client PC, printers, batch tools, EMS, etc.). PLCs are connected directly or through routing of the inter-controller network. This network is part of the control network.

Firmware upgrade tool for Quantum hardware.

programmable logic controller. The PLC is the brain of an industrial manufacturing process. It automates a process as opposed to relay control systems. PLCs are computers suited to survive the harsh conditions of the industrial environment.

Port 502 of the TCP/IP stack is the well-known port that is reserved for Modbus communications.

In this mode, data traffic that is related to the source port on a network switch is copied to another destination port. This allows a connected management tool to monitor and analyze the traffic.

(quality of service) The practice of assigning different priorities to traffic types for the purpose of regulating data flow on the network. In an industrial network, QoS is used to provide a predictable level of network performance.

(rapid spanning tree protocol) A protocol that allows a network design to include spare (redundant) links to provide automatic backup paths if an active link stops working, without the need for loops or manual enabling/disabling of backup links.

(supervisory control and data acquisition) SCADA systems are computer systems that control and monitor industrial, infrastructure, or facility-based processes (examples: transmitting electricity, transporting gas and oil in pipelines, and water distribution).

substation configuration description file: An SCL file containing a detailed description of an entire substation design. It must include sections describing the substation, communication, IED, and data type template. A single SCD file comprises multiple SSD and ICD files.

system configuration description language: An XML based language that allows a formal description of power utility automation systems, the devices and the relation between them, and the IED configuration.

(sequential function chart) An IEC programming language that graphically represents, in a structured manner, the operation of a sequential PLC. This graphical description of the PLC's sequential behavior and of the various resulting situations is created using simple graphic symbols.

A daisy chain loop, often referred to as SDCL, that contains remote I/O devices only (no switches or distributed I/O devices). This topology consists of a local rack (containing a remote I/O head module), and 1 or more remote I/O drops (each drop containing a remote I/O adapter module).

(simple network management protocol) Protocol used in network management systems to monitor network-attached devices for events. The protocol is part of the internet protocol suite (IP) as defined by the internet engineering task force (IETF), which consists of network management guidelines, including an application layer protocol, a database schema, and a set of data objects.

(simple network time protocol) See NTP.

(sequence of events) The process of determining the order of events in an industrial system and correlating those events to a real-time clock.

(structured text) A structured, developed language similar to computer programming languages. It can be used to organize a series of instructions.

An Ethernet-based network with a loop attached to the main ring, via a DRS. A sub-ring may contain either remote I/O or distributed I/O devices.

The 32-bit value used to hide (or mask) the network portion of the IP address and thereby reveal the host address of a device on a network using the IP protocol.

A multi-port device used to segment the network and limit the likelihood of collisions. Packets are filtered or forwarded based upon their source and destination addresses. Switches are capable of full-duplex operation and provide full network bandwidth to each port. A switch can have different input/output speeds (for example, 10, 100 or 1000 Mb/s). Switches are considered OSI layer 2 (data link layer) devices.

(target to originator)

(transmission control protocol) A key protocol of the internet protocol suite that supports connection-oriented communications, by establishing the connection necessary to transmit an ordered sequence of data over the same communication path.

Also known as internet protocol suite, TCP/IP is a collection of protocols used to conduct transactions on a network. The suite takes its name from 2 commonly used protocols: transmission control protocol and internet protocol. TCP/IP is a connection-oriented protocol that is used by Modbus TCP for explicit messaging.

The TOD type is entered as follows: TOD#<Hour>:<Minutes>:<Seconds>

Example: TOD#23:59:45.

(transparent ready) Web-enabled power distribution equipment, including medium- and low-voltage switch gear, switchboards, panel boards, motor control centers, and unit substations. Transparent Ready equipment allows you to access metering and equipment status from any PC on the network, using a standard web browser.

Memory entity of type BOOL, WORD, DWORD, etc., whose contents can be modified by the program currently running.