MODULE 1 and 2 Flashcards

Question

What is the function of WDT

Answer 1

Watch dog timer Ensure the CPU of the system has not frozen

Answer 2

Sink - Draws from a source Source - Outputs

Answer 3

Horizontal - Rung Vertical - Rail

Answer 4

A system containing a number of RTUs that collect field data and which are connected to the Master station, using a communications system

Answer 5

The data acquisition and control functions performed by a number of microprocessor-based units, distributed by the devices being controlled

Answer 6

A programmable logic controller that uses ladderlogic software and solid state electronic modules for both input and output Additionally: • Most PLCs now also offer function block programming

Answer 7

A programmable logic controller that uses ladder logic software and solid state electronic modules for both input and output Additionally: • Most PLCs now also offer function block programming

Answer 8

OLE for Process Control

Answer 9

Object Linking and Embedding

Answer 10

Input kept separate from the card Optical, Relay and Transformer

Answer 11

Carrier select multiple access

Answer 12

Carrier select multiple access, Collision detection

Answer 13

%IWO.4.0 - %IWO.4.5

Answer 14

%QO.3.0 - %QO.3.14

Answer 15

1. Display 2. Enter value 3. alarm 4. trend 5. animation

Answer 16

international standards society/ open systems interconnect

Answer 17

digital signals using digital transmitter if FF comms fail loop fails

Answer 18

relatively slow

Answer 19

noise immunity

Answer 20

the receiver

Answer 21

american standard code for information interchange

Answer 22

separation of data from a carrier signal

Answer 23

8 bits of data

Answer 24

256 distinct characters

Answer 25

Rapid improvement in LAN technology for master stations Man machine interface Remote terminal units Communications

Answer 26

- KISS, keep it simple stupid - Response time within correct levels - Redundancy - use open systems - scale-able - asses from view of max traffic - clearly defined - thorough tsting - confrim operation of components in actual envrioments - well documented - good training - simple operator screen

Answer 27

connect only 1 end

Answer 28

read discrete output

Answer 29

write single discrete output

Answer 30

write multiple discrete outputs

Answer 31

read discrete input

Answer 32

read input register

Answer 33

read analog output

Answer 34

write single analog output

Answer 35

write multiple analog output

Answer 36

``` Input multiplexer Input signal amplifier Sample and hold circuit A/D converter Bus interface and board timing system ```

Answer 37

8 analog outputs Resolution of 8 or 12 bits Conversion rates of 10 microseconds to 30 milliseconds Outputs range from 4.20 mA +- 10 volts

Answer 38

``` 8 or 16 analog inputs Resolution of 8 or 12 bits Range of 4-20mA Input resistance of 240 Kohms to 1 Mohm Conversion rates of 10 microseconds to 30 milliseconds Inputs are generally single ended ```

Answer 39

card has power supplied from the terminal strip on the card.

Answer 40

card has power supplied from an external power supply

Answer 41

- Operating Temp: -40 to + 75 C. - Use rechargable lithium battery to provide more reliable clock backup. - Some RTUs have multiple auxiliary voltage outputs to provide power to communication modems and sensors, some of these outputs are adjustable via RTU application. - Heat convention cooling help maitaining the internal tempreture in the power supply and hence boost its operating reliability. - Controlled powerline to DO modules enables centralized inhibiting of all relay outputs in the selected DO modules. - Short current limit on the outputs help protecting the power supply and backup battery in case malfunction of the connected devices. - Status LED’s in the front panel helps simple and visyual indication of the power supply out put connections and detecting some types of malfunctions. - Automatically switches the power suppply operation to the backup battery when the main power source fails - Upon main power’s availability(reconnection) the power supply provides automatic switchjover to main power and start recharging the backup battery. - Optimized temprature compensated charging provides over charging protection and over disharge and overheating protection of the backup battery.

Answer 42

- Pipeline corrosion and wear - Operation outside of design limits - Unintentional third party damage - Intentional damage

Answer 43

Loss of life and property Loss of product and downtime to fix pipeline Environmental impact Fines and legal suits

Answer 44

``` Physical inspection of the area Add an odorant Line flow calculations Line pressure measurement Noise detection ```

Answer 45

Involves walking the pipelines and looking for evidence of a leak by looking at the vegetation in the area etc.

Answer 46

Involves walking the pipelines and looking for evidence of a leak by looking at the vegetation in the area etc.

Answer 47

Check if the amount received is the amount expected and if there is a difference this could indicate a leak Does not allow for expedient detection of leaks

Answer 48

Detect pressure drops at various points in the line | Allows for quicker detection

Answer 49

There is an increase in noise of the pipeline when there is a leak

Answer 50

Pigging | Computer based

Answer 51

Uses pipeline modelling to assist in the detection Allows for data gathering and analysis Pig tracking Back tracking of fluid Accounting Flow compensation Rapid detection of leaks and quicker response

Answer 52

Pigs can carry surveillance and monitoring equipment to assist in the detection of leaks This will be covered more in the next objective.

Answer 53

Utility pigs – clean the pipeline of debris or seal the pipeline Cleaning – remove solids or semi-solid deposits Inspecting Monitoring Batch separation

Answer 54

because the valve size is smaller than the pipe size because it creates an obstruction.

Answer 55

``` Steel Urethane Urethane and neoprene Spheres (foam, solid, inflatable) Gel ```

Answer 56

are methods of calculation gas flow.

Answer 57

how to measure the flow of natural gas.

Answer 58

1985 and revised in 1992

Answer 59

Measurement of gas by axial-flow turbine meters

Answer 60

``` Swirl - Velocity profile Fluid drag - Non-fluid drag Accuracy - Linearity Pressure loss - Min/Max flow rate Pulsation ```

Answer 61

Orifice Metering of Natural Gas and other hydrocarbon fluids 1985 version Developed for pipe-tap orifice meters 1992 version Developed only for flange-tap orifice meters Calls for use of AGA No. 8 to calculate supercompressibility

Answer 62

Allows for variations in gas compositions Gas analysis should fall into a range of values provided in the report. Allows for an alternate method which uses a partial gas composition.

Answer 63

Allows for wide variations in gas compositions | Gas analysis should fall into a normal range of values or an expanded range of values.

Answer 64

``` RS-232/RS-442/RS-485 Dial-up Microwave Satellite Radio ```

Answer 65

Point-to-point | Point-to-multi-point

Answer 66

simplest set-up, one stations is setup as the master and the other is the slave to allow for data to be exchanged between two station

Answer 67

one device designated as the master until to several slave units

Answer 68

Master is in total control and makes regular polls of the data (sends and receives data) to each slave in sequence Slave responds to the master only when a request is received Also known as half-duplex

Answer 69

Data gathering is simple No collisions can occur on the network Link failure is easily detected

Answer 70

Interrupt type request from a slave requesting immediate action cannot be handled Waiting time increases with the number of slaves All communication between slaves have to pass through the master with added complexity

Answer 71

Slave monitors its inputs and when a significant change is detected or a limit is exceeded the slave initiates communication to the master and transfers data

Answer 72

System reduces unnecessary transfer of data as in polled systems Quick detection of urgent status information Allows slave-to-slave communication

Answer 73

Master may only detect a link failure after a period of time and only when system is polled Operator action is needed to have the latest values Collision of data may occur and may cause delay in the communication

Answer 74

Store and Forward is a technique that simply adds an intermediate device between the source and destination communication device so that it keeps information (store) until such time that it can be sent on to the final destination, to another intermediate device (forwarding). Used to accommodate changes in physical link or data link connectivity or if there is intermittent connectivity

Answer 75

Message frames are simply stored in the intermediate device in a queue until such time as the destination device becomes available

Answer 76

Intermediate device decodes the information out of the message frame and stores it in application memory for future retransmission. Allows the information to be retransmitted using a different data link in addition to a different physical link. Allows for data consolidation, increasing the overall efficiency of communication

Answer 77

The entity asking the questions (query) is the MTU and the entity providing the answers(response) is the RTU

Answer 78

Generic term for a technique within a communication protocol that permits or denies access to the physical communication medium Prevents more than one entity from trying to communicate over the same media simultaneously

Answer 79

Simple communication protocol technique by which the query and response cycle as well as media access control are implemented together There can only be a single master device, but there can be multiple slave devices Only the master device can initiate a query The slave devices can only respond to a query directed to it by the master

Answer 80

Satellite – fixed services (point-to-point) provide microwave radio technology, consists of two main components, the ground segment which is a fixed or mobile transmission, reception, and ancillary equipment and the space segment which is the actual satellite

Answer 81

Microwave – transmitting data over radio waves whose wavelengths are measured in small numbers of centimetre

Answer 82

``` Wider bandwidth Faster data speeds Multiple links allow for redundant paths Usually has Txfer/Rxfer redundancy Higher Cost ```

Answer 83

Radio – common means of communicating with remotes using either UHF/VHF or spread spectrum

Answer 84

Low power consumption Installed inside the RTU/PLC cabinet Low operating costs

Answer 85

High development costs Costly if over a wide area and no existing system is present Slow data speeds

Answer 86

most common and is very reliable and licensing is not required

Answer 87

a signal is generated with a particular bandwidth and spread in the frequency domain which gives a signal with a wider bandwidthinterference immunity and there is no licensing

Answer 88

One of the more common communications methods Dedicated leased lines, or dial-up lines through the Public Service Telephone Network Available bandwidth is very much dependent on the communications companies Provide reliable communications at up to 38.6 kbps Implementation cost for leased lines is minimal, however there are monthly leasing costs Leased lines are highly reliable but are subject to occasional line break, they can often be subject to interference from various environmental conditions such as ice and flooding etc.