PLC 1 Flashcards Preview

IET > PLC 1 > Flashcards

Flashcards in PLC 1 Deck (46):
1

Scans input conditions and executes user program to set output conditions

Processor

2

Lowers and stabilizes voltage used for electronics in PLC components.

Power supply

3

Printed circuit board with sockets that modules plug into

Backplane

4

Made of metal or plastic, this is the frame for most PLC systems

Chassis

5

Modules that are designed to connect the PLC to "real world" devices

I/O cards

6

Underlying systems that provide basic functions and services

Communications cards

7

Modules that connect the PLC to other systems and devices, such as variable speed drives and personal computers

Special purpose card

8

What do input cards do?

Convert signals from field devices to a signal for the processor

9

What are discrete modules used for?

Devices that have only one or two states

10

T/F any I/O point can be traced to a bit in processor memory

True

11

What designates the I/O type in an adress?

I: or O:

12

What systems provide communication between field devices and the processor?

The I/O system

13

What 6 advantages do PLC's provide?

Increased reliability
More flexibility
Lower cost
Communications capability
Faster response time
Easier to troubleshoot

14

What do output cards do?

They convert signals from the processor to signals for field devices

15

T/F Analog signals operate through only one value 4-20mA

False

16

T/F a programming terminal is required for the purpose if going online with the PLC to monitor I/O status

True

17

What is the primary function of a counter?

To keep track of how many

18

T/F it is possible to use a CTU and CTD instruction on the same address

False

19

T/F an RTO instruction needs an RES instruction

True

20

What program is used for allen bradleys PLC's?

Rockwell's RSLogix

21

What program is used to communicate between a PC and a PLC?

RSLinx

22

What is an example of an output?

A lamp

23

What is an example of an input?

A pushbutton

24

What is a channel configuration used for?

To set network addresses and connection speeds

25

What information does the I/O configuration provide?

The type and number of I/O cards

26

What should documentation include in a PLC system?

Device addresses, descriptions, and title pages

27

What does a complete scan cycle of a standard PLC include?

Self check, read I/O, solve user logic, and write outputs

28

What order does the PLC read logic in?

Top to bottom, left to right

29

What does XIC stand for

Examine if closed

30

What does an XIC instruction do?

Sets output to 1 if it examines a 1 at a set address

31

What does XIO stand for?

Examine if open

32

What does an XIO instruction do?

Sets output to 1 if it examines a 0 at a set address

33

What is the format for an address?

(File type)(File number):(Word)/(Bit)

34

What does OSR stand for?

One shot relay

35

What does OTE stand for?

Output energize

36

What does OTL stand for?

Output latch

37

What does OTU stand for?

Output unlatch

38

What does an OSR instruction do?

When the preceding instruction is true it sets its output bit to true for one cycle

39

What does an OTE instruction do?

When preceding instruction is true, it sets the output bit to 1

40

What does an OTL instruction do?

When preceding instrucion is true, it sets the output to 1 until it is unlatched

41

What does an OTU instruction do?

When preceding instruction is true, it unlatches a bit, setting it to 0

42

What does TON stand for?

Time on delay

43

What does TOF stand for?

Time off Delay

44

What does RTO stand for?

Retentive Time on Timer

45

What does RTF stand for?

Retentive timer false

46

What six values does each timer have?

Timer address, Timer base, preset value, accumulated value, enabled bit, and done bit