PLC TEST 2 UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
Question:
1. Define the term data transfer?
Answer:
Process of exchanging between PLC memory and/or areas
Question:
2. What is writing over?
Answer:
When numerical information replaces data that already exists in a memory location
Question:
3. Define the term data compare
Answer:
compares data stored in two or more words and makes decisions based on the program instructions
Question:
4. Define the term mask
Answer:
Mask is, bits in a word that are used to prevent other bits in a different word from being used. If there is a 1
in the bit location of the mask, the correspoinding bit in the output word is enabled and can be turned on or
off
Question:
5. Give an example of how an Allen-Bradley LIM instruction is used
Answer:
The limit instruction tests the values within a specific range. If the value is within the range, the limit is
said to be true, and if the limit is not within the range then the limit is said to be false.
Question:
6. List the four math functions that can be performed by most PLCs
Answer:
1. Addition
2. Subtraction
3.Multiplication
4.Division
Question:
7. T or F Data manipulation instructions can be combined with arithmetic (math) instructions
Answer:
True
, Question:
8. 2. Define the term double-integer
Answer:
Double integer, also known as DINT is a data type that stores a 32-bit signed integer value
Question:
9. Give an example of how a math function is used in a PLC program.
Answer:
A math function can be used to add, subtract, multiply, square root. Can be used for a variety of math
functions, can also use the compute function
Question:
10. What is the function of the clear (CLR) instruction
Answer:
The Clear function will clear the value within the word to zero. When the input is true, the value within the
destination will be set to zero.
Question:
11. What does the XPY instruction do
Answer:
he XPY function is when we need to put a value to a power of a another value, X to the Power of Y.
Question:
12. List the trigonometric instructions discussed in this chapter
Answer:
Sin, Cos, Tan, ASN, ARS, ATN
Question:
13. Define the term word as used in this chapter
Answer:
Words are locations in memory that can be used to store different kinds of information. A word register
can store the status of inputs and outputs.
Question:
14. Define the term file as used in this chapter
Answer:
A file is a group of consecutive memory words used to store information. Worlds 1 through 5 for example
would make up a consecutive 5-word file.
Question:
15. T or F The synchronous shift register shifts data in a forward direction only
Answer:
False
Question:
16. In a 1-word shift register, the data is entered at bit
CORRECT ANSWERS
Question:
1. Define the term data transfer?
Answer:
Process of exchanging between PLC memory and/or areas
Question:
2. What is writing over?
Answer:
When numerical information replaces data that already exists in a memory location
Question:
3. Define the term data compare
Answer:
compares data stored in two or more words and makes decisions based on the program instructions
Question:
4. Define the term mask
Answer:
Mask is, bits in a word that are used to prevent other bits in a different word from being used. If there is a 1
in the bit location of the mask, the correspoinding bit in the output word is enabled and can be turned on or
off
Question:
5. Give an example of how an Allen-Bradley LIM instruction is used
Answer:
The limit instruction tests the values within a specific range. If the value is within the range, the limit is
said to be true, and if the limit is not within the range then the limit is said to be false.
Question:
6. List the four math functions that can be performed by most PLCs
Answer:
1. Addition
2. Subtraction
3.Multiplication
4.Division
Question:
7. T or F Data manipulation instructions can be combined with arithmetic (math) instructions
Answer:
True
, Question:
8. 2. Define the term double-integer
Answer:
Double integer, also known as DINT is a data type that stores a 32-bit signed integer value
Question:
9. Give an example of how a math function is used in a PLC program.
Answer:
A math function can be used to add, subtract, multiply, square root. Can be used for a variety of math
functions, can also use the compute function
Question:
10. What is the function of the clear (CLR) instruction
Answer:
The Clear function will clear the value within the word to zero. When the input is true, the value within the
destination will be set to zero.
Question:
11. What does the XPY instruction do
Answer:
he XPY function is when we need to put a value to a power of a another value, X to the Power of Y.
Question:
12. List the trigonometric instructions discussed in this chapter
Answer:
Sin, Cos, Tan, ASN, ARS, ATN
Question:
13. Define the term word as used in this chapter
Answer:
Words are locations in memory that can be used to store different kinds of information. A word register
can store the status of inputs and outputs.
Question:
14. Define the term file as used in this chapter
Answer:
A file is a group of consecutive memory words used to store information. Worlds 1 through 5 for example
would make up a consecutive 5-word file.
Question:
15. T or F The synchronous shift register shifts data in a forward direction only
Answer:
False
Question:
16. In a 1-word shift register, the data is entered at bit
