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.

The target of real-time I/O data connection requests from scanners. It cannot send or receive real-time I/O data unless it is configured to do so by a scanner, and it does not store or originate the data communications parameters necessary to establish the connection. An adapter accepts explicit message requests (connected and unconnected) from other devices.

A selection in Control Expert that displays expert-level configuration properties that help define Ethernet connections. To maintain system performance, confirm that advanced mode properties are configured only by persons with a solid understanding of communication protocols.

(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.

(common industrial protocol) A comprehensive suite of messages and services for the collection of manufacturing automation applications (control, safety, synchronization, motion, configuration and information). CIP allows users to integrate these manufacturing applications with enterprise-level Ethernet networks and the internet. CIP is the core protocol of EtherNet/IP.

A CIP transport connection used for I/O data transmission via implicit messaging between EtherNet/IP devices.

A CIP transport connection used for explicit messaging between EtherNet/IP devices.

Using a CIP connection for communication that establishes a relationship between 2 or more application objects on different nodes. The connection establishes a virtual circuit in advance for a particular purpose, such as frequent explicit messages or real-time I/O data transfers.

A virtual circuit between 2 or more network devices, created prior to the transmission of data. After a connection is established, a series of data is transmitted over the same communication path, without the need to include routing information, including source and destination address, with each piece of data.

The EtherNet/IP network node that initiates a connection request for I/O data transfer or explicit messaging.

Communication between 2 network devices, where data is sent without prior arrangement between the devices. Each piece of transmitted data includes routing information, including source and destination address.

A diagnostic software program that lets you visualize your entire network on a single screen, allowing you to monitor, edit, and troubleshoot your industrial Ethernet network.

ConneXium Network Manager uses Modbus/TCP commands to read binary and word registers from PLCs and I/O devices, and generates alarms based upon register changes, user defined monitors, or limit values.

Twisted pair cables

(derived data type) 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.

An Ethernet-based network within a remote I/O network that contains both remote I/O and distributed I/O devices. Devices connected on this network follow specific rules to allow remote I/O determinism.

(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 (ncluding 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.

A group of distributed I/O devices connected either to a non-ring port on a DRS or to a distributed I/O communications module in the local rack. Distributed I/O clouds are single-point connections to the Ethernet I/O network and are not required to support RSTP.

Any Ethernet device (Schneider Electric device, PC, servers, or third-party devices) that supports I/O exchange with a PLC or other Ethernet communication service.

A network containing distributed I/O devices that integrates a unique standalone PLC or a unique Hot Standby system. I/O scanning may be performed by a communication module interlinked with a remote I/O head module on the local rack of an Ethernet remote I/O system. Distributed I/O network traffic is delivered after remote I/O traffic, which takes priority in an Ethernet remote I/O network.

(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.

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>

(device type manager) A device driver running on the host PC. It provides a unified structure for accessing device parameters, configuring and operating the devices, and troubleshooting the network. DTMs can range from a simple graphical user interface (GUI) for setting device parameters to a highly sophisticated application capable of performing complex real-time calculations for diagnosis and maintenance purposes. In the context of a DTM, a device can be a communications module or a remote device on the network.

See FDT.

(electronic data sheet) Simple text files that describe the configuration capabilities of a device. EDS files are generated and maintained by the manufacturer of the device.

(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.

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.

A network communication protocol for industrial automation applications that combines the standard internet transmission protocols of TCP/IP and UDP with the application layer common industrial protocol (CIP) to support both high speed data exchange and industrial control. EtherNet/IP employs electronic data sheets (EDS) to classify each network device and its functionality.

TCP/IP-based messaging for Modbus TCP and EtherNet/IP. 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. In EtherNet/IP, explicit messaging is considered class 3 type messaging, and can be connection-based or connectionless.

(explicit messaging client class) The device class defined by the ODVA for EtherNet/IP nodes that only support explicit messaging as a client. HMI and SCADA systems are common examples of this device class.

An Ethernet-based network containing distributed I/O devices located on an existing distributed I/O network that participate in an Ethernet remote I/O network through use of an extended port on a control network head module.

(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 a device.

(field device tool) The technology that harmonizes communication between field devices and the system host.

(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.

Global data provides the automatic exchange of data variables for the coordination of PLC applications.

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.

(highway addressable remote transducer) A bi-directional communication protocol for sending and receiving digital information across analog wires between a control or monitoring system and smart devices.

HART is the global standard for providing data access between host systems and intelligent field instruments. A host can be any software application from a technician's hand-held device or laptop to a plant's process control, asset management, or other system using any control platform.

Often referred to as HCDCL, a high-capacity daisy chain loop uses DRSs to extend the distance between remote I/O drops or connect sub-rings (containing remote I/O drops or distributed I/O devices) and/or distributed I/O clouds to the Ethernet remote I/O network.

(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.

Continuously polling the I/O modules to collect data and status, event, and diagnostics information. This process monitors inputs and controls outputs.

(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

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

(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.

UDP/IP-based class 1 connected messaging for EtherNet/IP. Implicit messaging maintains an open connection for the scheduled transfer of control data between a producer and consumer. Because an open connection is maintained, each message contains primarily data, without the overhead of object information, and a connection identifier.

An Ethernet-based network containing distributed I/O devices located on an existing distributed I/O network that participate in the control network only of an Ethernet remote I/O network.

(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.

An Ethernet-based network that is part of the control network, and provides data exchange between controllers and engineering tools (programming, asset management system (AMS)).

An Ethernet port on Ethernet remote I/O head modules allowing direct connection of distributed I/O modules to the remote I/O network and transparency between a control network and the Ethernet remote I/O network.

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

An Ethernet-based network containing distributed I/O devices that do not participate in an Ethernet remote I/O 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.).

A Quantum remote I/O system using coaxial cabling and terminators.

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

A Quantum rack containing the controller, a power supply, and an Ethernet remote I/O head module. A local rack consists of 1 or 2 racks, the main rack (containing the remote I/O head module) and an optional extended rack. A Quantum Ethernet remote I/O network requires 1 local rack on the main ring.

A functionality offered by Schneider Electric EtherNet/IP communication modules that allows a scanner to take the role of an adapter. The local slave enables the module to publish data via implicit messaging connections. Local slave is typically used in peer-to-peer exchanges between PLCs.

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

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. Implicit messaging typically uses multicast format for communications in an EtherNet/IP network.

(network interface module) A NIM resides in the first position on an STB island (leftmost on the physical setup), and provides the interface between the I/O modules and the fieldbus master. The NIM is the only module on the island that is fieldbus-dependent. A different NIM is available for each fieldbus.

(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) See originator and 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.

In EtherNet/IP, a device is considered the originator when it initiates a CIP connection for implicit or explicit messaging communications or when it initiates a message request for un-connected explicit messaging.

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.

Data from multiple I/O modules consolidated in a single data packet to be presented to the scanner in an implicit message in an EtherNet/IP network.

One of the 3 types of remote I/O devices in an Ethernet remote I/O network. A remote I/O drop is a Quantum or an X80 rack of I/O modules that are connected to an Ethernet remote I/O network and managed by an Ethernet remote adapter module. A drop can be a single rack or a rack with an extension rack.

The main ring of an Ethernet remote I/O network. The ring contains remote I/O devices and a local rack (containing a controller, a power supply module, and an Ethernet remote I/O head module).

An Ethernet-based network that contains 1 standalone PLC or one Hot Standby system and remote I/O devices. There are 3 types of remote I/O devices: a local rack, a remote I/O drop, and a ConneXium extended dual-ring switch (DRS). Distributed I/O devices may also participate in a remote I/O network via connection to DRSs.

(requested packet interval) The time period between cyclic data transmissions requested by the scanner. EtherNet/IP devices publish data at the rate specified by the RPI assigned to them by the scanner, and they receive message requests from the scanner at each RPI.

(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.

A Quantum remote I/O system using coaxial cabling and terminators.

(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).

The originator of I/O connection requests for implicit messaging in EtherNet/IP, and message requests for Modbus TCP.

An EtherNet/IP node capable of originating exchanges of I/O with other nodes in the network.

(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 mail transfer protocol) An email notification service that allows controller-based projects to report alarms or events. The controller monitors the system and can automatically create an email message alert with data, alarms, and/or events. Mail recipients can be either local or remote.

(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) See target and originator.

In EtherNet/IP, a device that is the recipient of a connection request for implicit or explicit messaging communications, or when it is the recipient of a message request for un-connected explicit messaging.

(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 and EtherNet/IP 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.

(user datagram protocol) A transport layer protocol that supports connectionless communications. Applications running on networked nodes can use UDP to send datagrams to one another. UDP does not always deliver datagrams as reliable or ordered as those delivered by TCP. However, by avoiding the overhead required for TCP, UDP is faster. UDP may be the preferred protocol for time-sensitive applications, where dropped datagrams are preferable to delayed datagrams. UDP is the primary transport for implicit messaging in EtherNet/IP.

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