Glossary

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%

According to the IEC standard, % is a prefix that identifies internal memory addresses in the logic controller to store the value of program variables, constants, I/O, and so on.

A

analog input

Converts received voltage or current levels into numerical values. You can store and process these values within the logic controller.

analog output

Converts numerical values within the logic controller and sends out proportional voltage or current levels.

C

CAN

(controller area network) A protocol (ISO 11898) for serial bus networks, designed for the intercon­nection of smart devices (from multiple manufacturers) in smart systems and for real-time industrial applications. Originally developed for use in automobiles, CAN is now used in a variety of industrial automation control environments.

CANopen

An open industry-standard communication protocol and device profile specification (EN 50325-4).

control network

A network containing logic controllers, SCADA systems, PCs, HMI, switches, ...

Two kinds of topologies are supported:

oflat: all modules and devices in this network belong to same subnet.

o2 levels: the network is split into an operation network and an inter-controller network.

These two networks can be physically independent, but are generally linked by a routing device.

controller

Automates industrial processes (also known as programmable logic controller or programmable controller).

CSA

(Canadian standards association) The Canadian standard for industrial electronic equipment in hazardous environments.

D

DIN

(Deutsches Institut für Normung) A German institution that sets engineering and dimensional standards.

E

electronic module

In a programmable controller system, most electronic modules directly interface to the sensors, actuators, and external devices of the machine/process. This electronic module is the component that mounts in a bus base and provides electrical connections between the controller and the field devices. Electronic modules are offered in a variety of signal levels and capacities. (Some electronic modules are not I/O interfaces, including power distribution modules and transmitter/receiver modules.)

element

The short name of the ARRAY element.

EN

EN identifies one of many European standards maintained by CEN (European Committee for Standardization), CENELEC (European Committee for Electrotechnical Standardization), or ETSI (European Telecommunications Standards Institute).

encoder

A device for length or angular measurement (linear or rotary encoders).

equipment

A part of a machine including sub-assemblies such as conveyors, turntables, and so on.

Ethernet

A physical and data link layer technology for LANs, also known as IEEE 802.3.

F

FAST I/O

FAST input/output Specific I/O modules with some electrical features (for example, response time) while the treatment of these channels are done directly by the controller

firmware

Represents the BIOS, data parameters, and programming instructions that constitute the operating system on a controller. The firmware is stored in non-volatile memory within the controller.

H

hot swapping

The replacement of a component with a like component while the system remains under power and operational. The replacement component begins to function automatically after it is installed.

I

IEC

(international electrotechnical commission) A non-profit and non-governmental international standards organization that prepares and publishes international standards for electrical, electronic, and related technologies.

input filter

A special function that helps reject extraneous signals on input lines due to such things as contact bounce and inducted electrical transients. Inputs provide a level of input filtering using the hardware. Additional filtering with software is also configurable through the programing or the configuration software.

IP 20

(ingress protection) The protection classification according to IEC 60529 offered by an enclosure, shown by the letter IP and 2 digits. The first digit indicates 2 factors: helping protect persons and for equipment. The second digit indicates helping protect against water. IP 20 devices help protect against electric contact of objects larger than 12.5 mm, but not against water.

IP 67

(ingress protection) The protection classification according to IEC 60529. IP 67 modules are protected against ingress of dust, contact, and water up to an immersion depth of 1 m.

L

LED

(light emitting diode) An indicator that illuminates under a low-level electrical charge.

M

machine

Consists of several functions and/or equipment.

ms

(millisecond)

N

network

A system of interconnected devices that share a common data path and protocol for communications.

P

PCI

(peripheral component interconnect) An industry-standard bus for attaching peripherals.

PDM

(power distribution module) A module that distributes either AC or DC field power to a cluster of I/O modules.

Pt100/Pt1000

(platinum 100/1000) Resistance thermometers, also referred to as resistance temperature detectors, are sensors used to measure temperature by correlating electrical resistance with temperature. As the temperature changes, the resistance to an electrical current passing through them predictably changes likewise. They are characterized by their nominal resistance R0 at a temperature of 0 °C.

oPt100 (R0 = 100 Ω)

oPt1000 (R0 = 1 kΩ)

T

terminal block

(terminal block) The component that mounts in an electronic module and provides electrical connections between the controller and the field devices.

U

UL

(underwriters laboratories) A US organization for product testing and safety certification.