Glossary

Ethernet implementation on thin coaxial cable. Typically uses a BNC connection.

Ethernet implementation on thick coaxial cable.

Ethernet implementation on unshielded twisted pair. Typically uses as RJ45 connection.

Drivers developed under the CiTDriversQA96 Driver Quality and Accreditation System, which ensures the driver was designed, coded, and tested to the highest possible standards.

Drivers developed using the CiTDriversQA92 Driver Quality and Accreditation System.

A facility that allows you to track incremental runtime data such as motor run hours, power consumption, and downtime.

An active alarm is an alarm in one of the following states: ON and unacknowledged; ON and acknowledged; OFF and unacknowledged.

Triggered when the result of a Cicode expression changes to true. Use advanced alarms only when alarm functionality cannot be obtained with the other alarm types. If you configure too many advanced alarms, your system performance can be affected.

You can assign each alarm to a category, and then process each category as a group. For example, for each category, you can specify the display characteristics, the action to be taken when an alarm in the category is triggered, and how data about the alarm is logged. You can also assign a priority to the category, which can be used to order alarm displays, filter acknowledgments, and so on.

The alarm display page displays alarm information in the following format: Alarm Time, Tag Name, Alarm Name, Alarm Description.

Displays alarm summary information in the following format: alarm name, time on, time off, delta time, comment.

Monitors all alarms and displays an alarm on the appropriate control client(s) when an alarm condition becomes active.

Triggered when an analog variable reaches a specified value. supports four types of analog alarms: high and high high alarms; low and low low alarms; deviation alarms; and rate of change alarms.

ASCII text files that contain a list of animation points (ANs) and the coordinate location (in pixels) of each point.

The points on a graphics page where an object displays. When you add an object to your page, automatically allocates a number (AN) to the animation point, (i.e., the location of the object).

A large application can be visualized as a series of discrete sections or areas. Areas can be defined geographically (where parts of the plant are separated by vast distances) or logically (as discrete processes or individual tasks).

Values (or variables) passed in a key sequence to a keyboard command in runtime (as operator input). Arguments can also be the values (or variables) passed to a Cicode function when it executes.

An association is the name or number you use when defining a Super Genie substitution, the value or values of which are dynamically generated at runtime.

Typically used to interface to a transceiver through what is often known as a drop cable.

ActiveX objects typically consist of a visual component (which you see on your screen) and an automation component. The automation component allows the interaction between the container object and the ActiveX object.

The number of times per second a signal changes in a communication channel. While the baud rate directly affects the speed of data transmission, the term is often erroneously used to describe the data transfer rate. The correct measure for the data rate is bits per second (bps).

BCD (Binary Coded Decimal) is a two-byte (16-bit) data type, allowing values from 0 to 9,999. The two bytes are divided into four lots of four bits, with each lot of four bits representing a decimal number. For example the binary number 0010 represents decimal 2. Thus the BCD 0010 0010 0010 0010 represents 2,222.

A bottleneck occurs when too many requests are being sent to a PLC communication link/data highway. It can occur with all types of protocols, and is dependent on several factors, including the frequency of requests, the number of duplicated (and hence wasteful) requests, whether the protocol supports multiple outstanding requests, as well as other network traffic.

A series of graphics pages linked by a browse sequence, which is a linear navigation sequence within your runtime system that uses Page Previous and Page Next commands.

Byte is a one-byte data type, allowing values from 0 to 255. One byte consists of 8 bits. Each ASCII character is usually represented by one byte.

When caching is enabled, all data read from a I/O device is stored temporarily in the memory of the I/O server. If another request is made (from the same or another control client) for the same data within the cache time, the I/O server returns the value in its memory, rather than read the I/O device a second time.

A function that is passed as an argument in another function. Callback functions must be user-written functions.

Programming language designed for plant monitoring and control applications. Similar to languages such as Pascal.

A Cicode function that blocks, or waits, for an asynchronous event to complete before returning.

CiNet is no longer supported. CiNet was designed as a low speed wide area network (for remote monitoring applications). If you have a widely-distributed application where computers are separated by vast distances, using a LAN to connect your control clients can be expensive. To connect control clients in this instance, use Microsoft's remote access server (RAS) or a Microsoft-approved solution, such as Shiva LanRover.

A text file that stores information about how each computer (servers and control clients) operates in the configuration and runtime environments. The Citect.INI file stores parameters specific to each computer and therefore cannot be configured as part of the project.

CiUSAFE is the application used to manage the hardware key that authorizes use of your software within the agreed limitations.

A computer that accesses shared network resources provided by another computer called a server. 's client-server based architecture is designed to distribute the processing tasks and optimize performance.

A discrete group of alarms servers, trends servers, reports servers, and I/O servers. It would usually also possess local control clients. For a plant comprising several individual sections or systems, multiple clusters can be used, one cluster for each section.

A command performs a particular task or series of tasks in your runtime system. A command is built from Cicode and can consist of just a function or a statement.

A connection between computers and peripheral devices, enabling data transfer. A communications link can be a network, a modem, or simply a cable. .

PC port used for sending and receiving serial data (also called serial or COM ports).

A computer running . Other common industry terms for this computer could be node, machine or workstation.

The interface between the runtime system and an operator. If you are using on a network, all computers (on the network) are control clients.

Prohibits writing to the Field VQT tag element of a tag extension.

Custom alarm filters provide a way to filter and display active alarms. Up to eight custom filter strings can be assigned to a configured alarm. In conjunction with a user-defined query function, the custom filters enable operators to identify and display active alarms of interest.

Data acquisition boards communicate directly with field equipment (sensors, controllers, and so on). You can install a data acquisition board in your server to directly access your field equipment.

Group of binary digits (bits) used to represent a single character of data in asynchronous transmission.

Devices that establish, maintain, and terminate a data transmission connection. Normally referred to as a modem.

Devices acting as data source, data sink, or both.

Transfer of information from one location to another. The speed of data transfer is measured in bits per second (bps).

Type of I/O device variable. I/O devices may support several data types that are used to exchange data with . You must specify the correct data type whenever I/O device variables are defined or referenced in your system.

Often called a `D' type connector due to the vague D shape of the casing. Has 15 pins arranged in two rows of 8 and 7 pins. While not as common as DB-9 or DB-25 they may be found on some computers and data communication equipment. Comes in both male (pins protruding) and female (pin sockets) configurations.

Often called a `D' type connector due to the vague D shape of the casing. Has 25 pins arranged in two rows of 13 and 12 pins. This kind of connection is a part of the standard for RS-232-D and is found on many computers, modems and other data communication equipment. Comes in both male (pins protruding) and female (pin sockets) configurations.

Often called a `D' type connector due to the vague D shape of the casing. Has 9 pins arranged in two rows of 5 and 4 pins. This kind of connection is common and is often used as the serial (com) port in computers. Often used in modems and other data communication equipment. Comes in both male (pins protruding) and female (pin sockets) configurations.

The debug.log file stores information about an unexpected system shut down or other internal issues. If an unexpected shutdown occurs, it will identify the version and path of each DLL being used at the time.

Triggered when the value of a variable deviates from a setpoint by a specified amount. The alarm remains active until the value of the variable falls (or rises) to the value of the deadband. .

Only returns calls from remote I/O devices.

Only receives calls from remote I/O devices, identifies the caller, then hangs up immediately so it can receive other calls. then returns the call using a dial-back modem.

Makes calls to remote I/O devices in response to a request; e.g., scheduled, event-based, operator request, and so on. Also returns calls from remote I/O devices.

A high-speed serial board manufactured by the Digiboard Corporation.

Triggered by a state change in a digital variable. Use these alarms when a process has only one of two states. You can use either the on (1) state or off (0) state (of a digital variable) to trigger the alarm.

Usually associated with discrete I/O in your I/O device, a digital variable can only exist in one of two states: on (1) or off (0). Allowed values for the digital data type are therefore 0 or 1. Discrete inputs (such as limit switches, photoelectric cells, and emergency stop buttons) and discrete outputs are stored as digital variables.

A disk file that resides on the hard disk of a computer and emulates a real I/O device. The value of each variable in the disk I/O device is stored on the computer hard disk. The disk I/O device is not connected to any field equipment in the plant.

Defines the rate at which trend data is displayed on the trend page.

For large applications with large amounts of data, you can distribute the data processing to reduce the load on individual computers.

If your plant consists several sections or systems, you can assign a cluster to each individual section, and then monitor all sections using one control client.Note: Don't use distributed servers to split up a single section or process into discrete areas. A single cluster system with distributed processing would be better used here since it would not be hampered by the maintenance overhead of a distributed server system (such as extra project compilations, and so on).

A method of approximating colors in imported or pasted bitmaps that involves combining pixels of different or colors from a color palette.

Database server that translates URL names into IP addresses.

Used for Internet addresses. Dot notation consists of four fields (called octets), each containing a decimal number between 0 and 255 and separated by a full stop (.).

A driver is used to communicate with control and monitoring devices, allowing the run-time system to interact directly with different types of equipment. Communication with an I/O device requires a device driver which implements the communication protocol(s).

Driver logs relate to the operation of a particular driver and are named accordingly. For example, the OPC driver is logged in 'OPC.dat'.

The ability to send and receive data over the same communication line.

A Microsoft Windows standard protocol set of messages and guidelines that enables communication between Windows applications on the same Windows computer.

A Windows standard communication protocol supported by . The I/O server communicates with the DDE server using the Windows standard DDE protocol. DDE servers are appropriate when data communication is not critical as DDE servers are not designed for high-speed data transfer.

Indicates that the variant has not yet been initialized (assigned a value). Variants that are empty return a VarType of 0. Variables containing zero-length strings (" ") aren't empty, nor are numeric variables having a value of 0.

Widely used type of local area network based on the CSMA/CD bus access method (IEEE 802.3).

As an alternative to viewing event trend data by event number, it is possible to see event trends across a timeline. When event trends are shown by time, the trend graph includes a start and end time and enables operators to see both the time of a triggered event, and the elapsed period between events. This data can also be displayed on the same graph as a periodic trend.

To construct an event trend/SPC, takes a sample when a particular event is triggered (in the plant). This sample is displayed in the window. The event must then reset and trigger again, before the next sample is taken. Events are identified by the event number. .

A statement (or group of statements) that returns a value. An expression can be a single variable, a mathematical formula, or a function.

The latest tag field data received from a device.

A computer with a large data storage capacity dedicated to file storage and accessed by other client computers via a network. On larger networks, the file server runs a special network operating system. On smaller installations, the file server may run a PC operating system supplemented by peer-to-peer networking software.

Simultaneous two-way (in both directions) independent transmission (4 Wires).

A pseudo-protocol supported by disk I/O devices that provides a convenient way to represent disk data. The generic protocol is not a real protocol (communicates with no physical I/O device).

If you have numerous devices of the same type (e.g., 100 centrifugal pumps), the display graphics for each will behave in much the same way. Using Genies, you only have to configure common behavior once. The graphics can then be saved as a Genie and pasted once for each device.

Can be shared across all Cicode files in the system (as well as across include projects).

A control client used to monitor information from several systems or sections (using clusters).

A faint (grayed) dotted rectangular box outline defining the exterior boundary region of a graphic object. Only visible and active when the graphics object is selected and being resized. Contains sizing handles in each corner and (if sized large enough to display) one in the centre of each side.

A drawing (or image) that appears on a workstation to provide operators with control of a plant, and display a visual representation of conditions within the plant.

allows you to group multiple objects together. Each group has a unique set of properties, which determine the runtime behavior of the group as a whole.

Transmission in either direction, but not simultaneously.

A hardware alarm indicates that an error has been detected in your system. Typically displayed on a dedicated hardware alarms page, this type of alarm may indicate that a loss of communication has occurred, that Cicode can not execute, that a graphics page is not updating correctly, or that a server has become inoperative. A description and error code are provided to help decipher the cause of the problem.

A bar graph that shows frequency of occurrence versus value. Quite often the data is fitted to a distribution such as a normal distribution. .

An item of equipment that communicates with plant-floor control or monitoring equipment (sensors, controllers, and so on). The most common I/O devices are PLCs (programmable logic controllers); however, supports a wide range of I/O devices, including loop controllers, bar code readers, scientific analyzers, remote terminal units (RTUs), and distributed control systems (DCS). can communicate with any I/O device that has a standard communications channel or data highway.

The (logical) location of the I/O device in the system. Each I/O device must have a unique address in the system, unless the I/O device is defined in other servers (to provide redundancy). If redundancy is used, the I/O device must then have the same I/O device name, number, and address for each server.

A unit of information used in . Variables are stored in memory registers in an I/O device. exchanges information with an I/O device by reading and writing variables. refers to I/O device variables by their register addresses. I/O devices usually support several types of variables; however, the most common are digital variables and integer variables.

A dedicated communications server that exchanges data between I/O devices and control clients. No data processing is performed by the I/O server (except for its local display). Data is collected and passed to the control clients for display, or to another server for further processing. All data sent to an I/O device from any computer is also channelled through the I/O server. If data traffic is heavy, you can use several I/O servers to balance the load.

The timestamp of when the element was last updated on a tag extension.

There is a maximum number of characters that you can type in a Command or Expression field (usually 128). If you need to include many commands (or expressions) in a property field, you can define a separate include file that contains commands or expressions. An include file is a separate and individual ASCII text file containing only one sequence of commands or expressions that would otherwise be too long or complicated to type into the command or expression field within . The include file name is entered instead, and the whole file is activated when called.

A 4-byte (32-bit) data type allowing values from 2,147,483,648 to 2,147,483,647.

A 2-byte data type, allowing values from -32,768 to 32,767, that is used to store numbers (such as temperature or pressure). Some I/O devices also support other numeric variables, such as real (floating point) numbers, bytes, and binary-coded decimals.

Allows you to run projects over the Internet from a remote location. It is basically a "runtime-only" version of : you can run your project from that computer, just as you would from any normal client.

An external event indicating that the CPU should suspend its current task to service a designated activity.

A unique logical address used by the Internet Protocol (IP). Contains a network and host ID. The format is called dotted decimal notation, and is written in the form: w.x.y.z.

The Kernel allows you to perform low-level diagnostic and debugging operations for runtime analysis of your system. A set of diagnostic windows display low-level data structures, runtime databases, statistics, debug traces, network traffic, I/O device traffic and so on.

Consist of a key sequence that an operator enters on the keyboard, and an instruction (or series of instructions) that executes when the key sequence is entered. Keyboard commands can be assigned to an object or page, or they can be project-wide.

Provides high-level technical information beyond the scope of standard technical documentation that is updated regularly and available at http://www.citect.com.

An index indicating the degree of peakedness of a frequency distribution (usually in relation to a normal distribution). Kurtosis < 3 indicates a thin distribution with a relatively high peak. Kurtosis > 3 indicates a distribution that is wide and flat topped.

When a project is compiled, creates a language database (dBASE III format) consisting of two fields: native and local. Any text marked with a language change indicator is automatically entered in the native field. You can then open the database and enter the translated text in the local field.

A copy of a library item, possessing the properties of the library original. Because it is linked, the copy is updated whenever the original is changed.

A system that connects computers to allow them to share information and hardware resources. With real-time LAN communication, you can transfer data, messages, commands, status information, and files easily between computers.

Only recognized by the function within which it is declared, and can only be used by that function. Local variables must be declared before they can be used. Any variable defined within a function (i.e., after the function name) is a local variable, therefore no prefix is needed. Local variables are destroyed when the function exits and take precedence over global and module variables.

The language of the end user. Runtime display items such as alarm descriptions, button text, keyboard/alarm logs, graphic text, Cicode strings and so on can be displayed in the local language, even though they may have been configured in the language of the developer (native language).

Local variables allow you to store data in memory when you start your runtime system. They are created each time the system starts, and therefore do not retain their values when you shut down.

Log files are a record of time-stamped system data that can be analyzed to determine the cause of a problem. The available log files include syslog.dat, tracelog.dat, debug.log, kernel.dat, and dedicated driver logs.

A 4-byte (32-bit) data type, allowing values from 0 to 99,999,999. The four bytes are divided into eight lots of four bits, with each lot of four bits representing a decimal number. For example the binary number 0011 represents decimal 3. Thus the BCD 0011 0011 0011 0011 0011 0011 0011 0011 represents 33,333,333.

A 4-byte (32-bit) data type allowing values from 2,147,483,648 to 2,147,483,647.

Defined by specifying the values of the variable that trigger each of these alarms. As a low alarm must precede a low low alarm, the low alarm no longer exists when the low low alarm is triggered. Note that the variable must rise above the deadband before the alarm becomes inactive. .

The maximum number of data bits that can be read from the I/O device in a single request. For example, if the maximum request length is 2048 bits, the maximum number of integers that can be read is: 2048/16 = 128.

Metadata is a list of names with corresponding values that is attached to an objects animation point.

Allows you to use a trends sample period of less than one second.

A visual representation of a production system using an organised set of graphical pages. .

A pre-defined period of time after which tag update value notifications are sent to subscription clients

Specific to the file in which the variable is declared. This means that it can be used by any function in that file, but not by functions in other files. By default, Cicode variables are defined as module, therefore prefixing is not required (though a prefix of MODULE could be added if desired). Module variables should be declared at the start of the file.

Use combinations of values from three digital variables to define eight states. For each state, you specify a description (e.g., healthy or stopped), and whether or not the state triggers an alarm.

Generally the language of the project developer. Display items such as alarm descriptions, button text, keyboard/alarm logs, graphic text, Cicode strings and so on can be configured in the native language, and displayed, at runtime, in the language of the end-user (local language).

A group of computers and peripheral devices, connected through a communications link. Data and services (e.g., printers, file servers, and modems) can be shared by computers on the network. A local network of PCs is called a LAN.

A computer running that is connected to a LAN through a network adaptor card and network software. .

Enables communication between Windows applications on separate computers connected across a common network.

A structural anchor point for a graphic object, usually visible as a small square box superimposed over a graphic. Nodes will be located separately at the start, at the end, and at every change in direction within a graphic object. .

Also known as a `bell' curve, the normal distribution is the best known and widely applicable distribution. The distribution is symmetrical and popularly represents the laws of chance. 68.27% of the area lies between -1 sigma and +1 sigma, 95.45% between -2 sigma and+2 sigma, and 99.73% between -3 sigma and +3 sigma. The values of skewness and kurtosis are used to provide quantitative measures for normality. Assuming that at least 20 samples are used to construct a distribution, a good rule of thumb is to accept the data as a normal distribution when, -1.0 = skewness = 1.0 2 = kurtosis = 4.

Indicates that a variant contains no valid data. Variants that are null return a VarType of 1. Null is not the same as empty, which indicates that a variant has not yet been initialized. It is also not the same as a zero-length string (" "), which is sometimes referred to as a null string. Null is not equivalent to zero or blank. A value of null is not considered to be greater than, less than, or equivalent to any other value, including another value of null. A boolean comparison using a null value will return false.

Basic building blocks of a graphics page. Most objects possess properties that allow them to change dynamically under user-definable runtime conditions allowing them to provide animated display of conditions within the plant.

An object ID associated with every tag in a project that uniquely identifies the tag for use by tag-based drivers, automatically generated at compile. It is used instead of the actual address of the register (which is what most other drivers use to read from and write to I/O devices).

An ActiveX control that can only be declared with local, module, or global scope.

Allows applications to access data in database management systems using structured query language (SQL) to access data.

A state where an invalid tag quality value is overridden by a manually added value.

Packing a database re-indexes database records and deletes records marked for deletion. If you edit your databases externally to , you should pack the database afterwards.

A read-only variable associated with a particular page When you make the association, you name the variable, and assign it a value. When the page is opened during runtime, creates the variable. Its value can then be read. When the page is closed, the environment variable memory is freed (discarded).

A communications error-checking procedure. The number of 1's must be the same (even or odd) for each group of bits transmitted without error.

A trend that is sampled continuously at a specified period. You can also define a trigger (an event) to stop and start the trend (when a specified condition occurs in the plant).

Cache data saved to a computer hard disk that allows an I/O server to be shut down and restarted without having to re-dial each I/O device to get its current values. This cache consists of all the I/O device's tag values.

You can sometimes install a PLC interface board in your server. A proprietary interface board is usually supplied by your PLC manufacturer, and you can connect it to a PLC or a PLC network. You can only use proprietary interface boards with the same brand of PLC.

An individual digital (or analog) variable read from an I/O device. only counts physical points (and counts them only once, no matter how many times they are used). The point limit is the maximum number of I/O device addresses that can be read and is specified by your license. When you run the point count of your project is checked against the point limit specified by your Hardware Key.

Provide the communication gateway to your I/O device(s).

The server that normally processes alarms.

The server that normally processes reports.

The server that normally processes trends.

Level of access applied to system elements within your project. A user assigned a role that possesses the matching privilege can control it.

The elements of a monitoring and control system, such as graphics pages, objects, and so on. These elements are stored in files of various types; for example, graphics files for graphics pages, databases for configuration records, and so on. You use the compiler to compile the project into a runtime system.

Describes the appearance of an object (size, location, color, and so on.) and its function (the command or expression executed by the object, the privilege required to gain access to the object, and so on).

Messaging format consisting of a set of messages and guidelines used for communication between the server and an I/O device. The communication protocol determines how and the I/O device communicate; the type of data to exchange; rules governing communication initiation and termination; and error detection.

Caches internet transactions to improve performance by reducing the average transaction times by storing query and retrieved information for re-use when the same request is made again. When an Internet display client (IDC) connects to a proxy server, that server provides the TCP/IP addresses necessary to access report server session information.

A public switched telephone network is the network of all the world's public switched telephone networks. It is now primarily digital and includes mobile as well as fixed telephones.

Referencing tag data by using the tag name, element name and the item name.

The quality of the value of a tag extension.

The timestamp of when the quality last changed on a tag extension

Triggered when the value of the variable changes faster than a specified rate. The alarm remains active until the rate of change falls below the specified rate. Deadband does not apply to a rate of change alarm.

Real (floating point) is a 4-byte (32-bit) data type allowing values from 3.4E38 to 3.4E38. Use a real variable to store numbers that contain a decimal place.

Real (floating point) is a 4-byte (32-bit) data type, allowing values from 3.4E38 to 3.4E38. Use a real variable to store numbers that contain a decimal place.

Usually the primary property of a database record, referenced in system through its name. Database record names must be unique for each type of database record. Sometimes you can use identical names for different record types. However, to avoid confusion, you should use a unique name for each database record in your application.When you specify a name for a database record, the name must begin with an alphabetic character (A-Z, a-z) and cn only include alphanumeric characters (A-Z, a-z, 0-9) and the underscore character (_). For example, "Pressure," "Motor_10," and "SV122_Open" are all valid database record names. Each database record name can contain up to 16 characters.Database record names are not case-sensitive, so "MOTOR_1," "Motor_1" and "motor_1" are all identical database record names. For this reason use a meaningful name for any database record as well as the necessary naming conventions.

A method of using the hardware in a system such that if one component in the system becomes inoperative, control of the system is maintained, and no data is lost.

Interaction between two computers through a modem and telephone line.

A terminal remote from the computer that controls it. The computer and remote terminal communicate via a modem and telephone line.

A statement or account of plant-floor conditions. reports can be requested when required, on a periodic basis, or when an event occurs.

Controls the layout and content of reports. The format file is edited using a text editor and can be in either ASCII or RTF format.

Controls report processing. You can request reports at any time or when specific events occur.

Words that cannot be used as a name for any database record or Cicode function.

A type of IDC plug commonly used in data communications. Recognizable as the style of data plug used in phone line and handset connectors. RJ11 is a 6/4 plug with 6 contacts but only 4 loaded.

A type of IDC plug commonly used in data communications. Recognizable as the style of data plug used in phone line and handset connectors. RJ12 is a 6/6 plug with 6 contacts.

A type of IDC plug commonly used in data communications. Recognizable as the style of data plug used in phone line and handset connectors. RJ45 is often used with 10baseT and is an 6/8 plug with 8 contacts.

A defined set of permissions (privileges and areas) that are assigned to users.

An industry standard for serial communication. The standard specifies the lines and signal characteristics that are used to control the serial transfer of data between devices.

An industry standard for serial communication. The standard specifies the lines and signal characteristics that are used to control the serial transfer of data between devices. RS-422 uses balanced voltage interface circuits.

An industry standard for serial communication. The standard specifies the lines and signal characteristics that are used to control the serial transfer of data between devices. RS-485 uses balanced voltage interface circuits in multi-point systems.

The system that controls and monitors your application, process, or plant. The runtime system is sometimes called the Man-Machine Interface (MMI), and is compiled from a project.

A system architecture that can be resized without having to modify existing system hardware or software. lets you re-allocate tasks as more computers are added, as well as distribute the processing load.

Determines how often the I/O server contacts a scheduled I/O device to read data from it. .

Uses the communication port on your computer or a high speed serial board (or boards) installed inside your computer.

A computer connected to an I/O device (or number of I/O devices). When is running, the server exchanges data with the I/O device(s) and distributes information to the other control clients as required. A local area network (LAN) computer that perform processing tasks or makes resources available to other client computers. In , client-server architecture distributes processing tasks to optimize performance.

Data transmission in one direction only.

An index indicating the degree of asymmetry of a frequency distribution (usually in relation to a normal distribution). When a distribution is skewed to the left (for example), then the tail is extended on that side, and there is more data on the left side of the graph than would be expected from a normal distribution. Positive skew indicates the distribution's mean (and tail) is skewed to the right. Negative skew indicates the distribution's mean (and tail) is skewed to the left.

Allow an operator to change the value of an analog variable by dragging an object (or group) on the graphics page. Sliders also move automatically to reflect the value of the variable tag.

A pure software (virtual) PLC created by software and existing only within the computer memory. Usually provides a software interface for communication (READ and WRITE) operations to take place with the soft PLC. Also known as a `virtual field unit' or `virtual I/O device'.

uses a hardware key that plugs into the printer port of your computer to protect against license infringement. The hardware key contains the details of your user license. When you run , the point count in your project is checked against the point limit specified in the hardware key.

Represents the total number of seconds that will elapse after the last update before extended quality of the tag element is set to “Stale”.

The Server that processes alarms if the primary alarms server is unavailable.

The server that processes reports if the primary reports server is unavailable.

The server that processes trends if the primary trends server is unavailable.

The number of bits that signals the end of a character in asynchronous transmission. The number is usually 1 or 2. Stop bits are required in asynchronous transmissions because the irregular time gaps between transmitted characters makes it impossible for the server or I/O device to determine when the next character should arrive.

The underlying details of a QUALITY tag.

A Super Genie substitution is comprised of the data type (optional) and association that you use to define an object or group of object’s properties when creating a Super Genie.

Dynamic pages (usually pop-ups), to which you pass information when the page displays at runtime. You can use Super Genies for pop-up type controllers (to control a process, or a single piece of plant floor equipment).

An object (or group of objects) stored in a library for later retrieval and use. By storing common objects in a library, you reduce the amount of disk space required to store your project, and reduce the amount of memory required by the run-time system.

Syslog.dat is the primary log file. It contains useful system information, from low-level driver traffic and Kernel messages, to user defined messages. Trace options (except some CTAPI traces) are sent to this file.

Additional information for a tag that represents data as a collection of elements, and a collection of items in a tag.

Includes operations such as I/O processing, alarm processing, display management, and Cicode execution. Any individual `instance' of Cicode is also a `task'.

A base drawing or time-saving pattern used to shape a graphics page. Each template contains base information for the page, such as borders and common control buttons. provides templates for all common page types.

When text is added to a graphics page, it is placed in a text box. A text box has a number of handles, which can be used to manipulate the text object.

Used to manage simultaneous execution of tasks in multitasking operating systems, enabling the operating system to determine priorities and schedule CPU access.

The period of time during which a task must be completed. If the timeout period is reached before a task completes, the task is terminated.

An alarm triggered by a state change in a digital variable. Time-stamped alarms have an associated register in the I/O device to record the exact time when the alarm changes to active. Use time-stamped alarms when you need to know the exact order in which alarms occur.

Time stamped analog alarms work in the same way as analog alarms except that they are time stamped (with the Alarm On and Alarm Off times) using millisecond precision from the time kept by the field device (i.e. the RTU or PLC). The configuration details for time stamped analog alarms are exactly the same as for analog alarms.

Time stamped digital alarms work in the same way as digital alarms except that they are time stamped (with the Alarm On and Alarm Off times) using millisecond precision from the time kept by the field device (i.e. the RTU or PLC). The configuration details for time stamped digital alarms are exactly the same as for digital alarms.

A help message that displays in a pop-up window when an operator holds the mouse stationary over an object.

An object is considered touched if an operator clicks it.

Can be assigned to objects on graphics pages. Touch commands allow you to send commands to the runtime system by clicking an object.

The tracelog.dat file contains managed code logging, mainly in relation to data subscriptions and updates. Note that field traces and requests to native drivers go to the syslog.dat or a specific driver log file.

A graphical representation of the changing values of a plant-floor variable (or expression), or a number of variables. .

The actual line on a trend that represents the changing values of a plant-floor variable (or expression). .

Consists of a trend (or a number of trends), a title, a comment, scales, times and so on.

Controls the accumulation and logging of trend information. This information provides a current and historical view of the plant, and can be processed for display on a graphics page or printed in a report.

User Account Control. Security technology introduced in Windows Vista to enable users to run with standard user rights more easily. .

Reference to tag data by using only the tag name.

A 2-byte (16 bit) data type, representing an integer range from 0 to 65,535. This is supported for all I/O devices that can use INT types. This means you can define any integer variable as an unsigned integer to increase the positive range.

A person or group of persons that require access to the runtime system

The last field data which had “Good” quality in a tag extension.

The value of the extension of a tag.

The timestamp of when the value last changed on a tag extension

The type of the variable (INT (32 bits), REAL (32 bits), STRING (256 bytes), OBJECT (32 bits)).

A computer configured with manager-only access to the runtime system. No control of the system is possible, but full access to data monitoring is permitted.

Behavioral identification rather than a physical one. For example, Windows 95 is a virtual desktop.

A facility that simplifies an otherwise complex procedure by presenting the procedure as a series of simple steps.